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PeeUTHERN CALIFORNIA ACADEMY OF SCIENCES

BULLETIN

Volume 101 Number 1

| GALIFORNIA
ACADEMY OF SCIENCES

APR 1 8 2002

Se STE Cs ee ee rt

LIBRARY

SOROS ETS RTT EI

BCAS-A101(1) 1—47 (2002) Syne aash APRIL 2002

Southern California Academy of Sciences
Founded 6 November 1891, incorporated 17 May 1907

© Southern California Academy of Sciences, 2002

OFFICERS

Daniel Pondella, President
Ralph Appy, Vice-President
Susan E. Yoder, Secretary
Daniel A. Guthrie, Treasurer
Daniel A. Guthrie, Editor
David Huckaby, Past President
Hans Bozler, Past President

BOARD OF DIRECTORS

1999-2002 2000-2003 2001—2004
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Gloria J. Takahashi Schwartz Raymond Wilson

Susan E. Yoder

Membership is open to scholars in the fields of natural and social sciences, and to any person interested
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Date of this issue 1 April 2002

© This paper meets the requirements of ANSI/NISO Z39.48-1992 (Permanence of Paper).

SOUTHERN CALIFORNIA ACADEMY
OF SCIENCES

FOUNDED 149;

ot [5
Yip

CALL FOR PAPERS
2002 ANNUAL MEETING
June 7-8, 2002
CLAREMONT MCKENNA COLLEGE
CLAREMONT

4 7
NCORPORATED 1”

Contributed Papers & Posters: Both professionals and students are welcome to submit abstracts for
a paper or poster in any area of science. Abstracts are required for all papers, as well as posters, and
must be submitted in the format described below. Maximum poster size is 32 by 40 inches.

Symposia: The following symposia are planned at the present time. If you wish to participate or to
organize any additional symposia, please contact the organizer or the Academy Vice President, Ralph
Appy (310 732 3497) rappy @portla.org. Organizers should have a list of participants and a plan for
reaching the targeted audience.

Friday, June 7, 2002
Virtual Oceans
Judy Doino Lemus jdlemus@usc.edu 213-740-1965

Marine Monitoring in the Southern California Bight
Stephen Weisberg 714-372-9203 stevew @sccwrp.org

Aerial Particulate Contaminants
Ralph Appy rappy @portla.org 310-732-3497

Poster Session: 5 pm
Scientific Illustrators exhibit at Poster Session
Plenary Speaker: Gregor Hodgson, ‘John Q. Public Saves Coral Reefs”

Saturday, June 8, 2002

Rocky Reef Monitoring
Dan Pondella pondella@oxy.edu (323) 259-2955 and Bob Grove grovers @sce.com 626-302-9735

Conservation Management
Brad Blood BBlood @sapphosenvironmental.com 626-683-3547

Effects of Exotic Species on Southern California Wildlife
Dan Guthrie dguthrie@jsd.clarement.edu 909-607-2836 and Andrew Jirik ajirik @ portla.org

High School Research Participation Program Presentations:
Gloria Takahashi 626-333-2173, myopick @aol.com
Short Course on Sea Urchin Toxicity Test Methods for Conducting Marine Environmental Re-
search
Stephen Bay (SCCWRP) and Michelle Anghera (UCLA)
Plenary Speaker: Walter Fitch, U.C. Irvine, ‘‘Creation Science: An Oxymoron?”

There will be additional sessions of Invited Papers and Posters and of papers by Junior Academy
members.

Student Awards: Students who elect to participate are eligible for best paper or poster awards in the
following categories. Biology: ecology and evolution, biology: genetics and physiology, physical sci-
ence. A paper by any combination of student and professional co-authors will be considered eligible
provided that it represents work done principally by student(s). In the case of an award to a co-authored
paper, the monetary award and a one year student membership to the Academy will be made to the
first author only.

For further information on posters, abstracts, registration and deadlines, see the Southern Cal-
ifornia Academy of Science web page at: jsd.claremont.edu/scas/

Short Course Description for Presentation at SCAS 2002 Annual Meeting
Saturday, June 8, 2002; 8 a.m.—noon

Sea Urchin Toxicity Test Methods for Conducting
Marine Environmental Research

Instructors:
Steven Bay (SCCWRP)
Michelle Anghera (UCLA)
Co-sponsored by the Southern California Regional Chapter of SETAC

This is a “‘hands-on”’ short course intended to provide graduate students and faculty with the skills
and background needed to conduct environmental research with the gametes and embryos of sea
urchins and sand dollars. The course will use the locally abundant purple sea urchin (Strongylocentrotus
purpuratus) as the test organism. Laboratory toxicity tests provide the foundation for many types of
environmental toxicology research. Toxicity tests also provide an excellent laboratory tool for inde-
pendent student research and provide a mechanism to integrate many different disciplines (biology,
chemistry, mathematics) into interesting classroom activities. Early life stage tests using sea urchins
are particularly attractive for this research because the animals are easily obtained and held in the
laboratory and several sensitive test methods have been developed using sperm and embryos. These
tests are widely used in monitoring and research programs throughout the world and can be conducted
on a modest budget and in a short period of time.

This course will introduce the participants to the applications of sea urchin toxicity tests in environ-
mental research and discuss opportunities for careers and academic research in this field. The partic-
ipants will conduct a complete toxicity test during the class and observe additional techniques needed
to conduct other test methods. The applications of sea urchin toxicity tests in environmental research
will be illustrated with examples from the instructors’ recent investigations into the environmental
effects of contaminated sediment and stormwater runoff.

This class is free to SCAS meeting registrants, but size is limited to 20 participants. Participants should
be familiar with basic laboratory techniques, including the preparation of dilutions from stock solutions,
operation of pipettes, and use of a compound microscope. All class materials will be provided by the
instructors.

CALL FOR MENTORS

The Research Training Program of the Southern California Academy of Sciences is receiving a
large number of applications from students for the 2002—2003 academic year. This is in large part due
to an excellent article in the Los Angeles Times about the program and success of students enrolled in
it. The program involves the placement of high school students with excellent scientific backgrounds
from throughout southern California in scientific laboratories to conduct research under research men-
tors. The projects are usually designed by the mentor. Students spend about 8 hours a week on their
projects, commencing in September and concluding in May with the presentation of their results at
the Annual Meeting of the Academy.

We are seeking scientists who might like to become mentors for these outstanding students in the
coming year. If you or your graduate students have room in your lab for a student, please let us know.
We need your name, address, contact numbers (include e-mail) and an indication of research area.
Forward the above information to:

Dan Guthrie
dguthrie @jsd.claremont.edu
909 607 2836

Digitized by the Internet Archive
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Bull. Southern California Acad. Sci.
101(1), 2002, pp. 1-12
© Southern California Academy of Sciences, 2002

A New Species of the Genus Lile (Clupeiformes: Clupeidae)
of the Eastern Tropical Pacific

José Luis Castro-Aguirre', Gorgonio Ruiz-Campos? and Eduardo F. Balart?

'Centro Interdisciplinario de Ciencias Marinas, I.P.N. Departamento de
Pesquerias y Biologia Marina, Apdo. Postal 592, La Paz,
Baja California Sur 23001 México.
*Universidad Autonoma de Baja California. Facultad de Ciencias, Apdo.
Postal 1653, Ensenada, Baja California 22800 México.
>Centro de Investigaciones Biolégicas del Noroeste, S.C. Laboratorio de
Ictiologta, Apdo. Postal 128, La Paz, Baja California Sur 23001 México.

Abstract.—A new species of tropical sardine belonging to the genus Lile is de-
scribed. The species differs from other known members of the genus by its mor-
phometrics, morphology, number of gill rakers, coloration and distributional pat-
tern. This new taxon represents the third known species of the genus Lile for the
eastern tropical Pacific.

Resumen.—Se describe una especie nueva de sardina tropical que pertenece al
género Lile. Difiere de los otros miembros de este género por su morfometria,
morfologia, numero de branquiespinas, coloraci6n y patron de distribuci6n geo-
grafica. Esta es la tercera especie, de este género, que se conoce en los litorales
del Pacifico oriental tropical.

The Clupeidae, order Clupeiformes, is divided into five subfamilies. One of
them, Clupeinae, contains 15 genera and almost 80 species widely distributed
through temperate, subtropical and tropical seas of the world’s oceans (Whitehead
1985). The genus Lile Jordan and Evermann 1896 of subfamily Clupeinae, is
exclusive to tropical and subtropical waters of Middle and South America. Besides
the new species described here, three other Li/e species are known: (1) L. stolifera
(Jordan and Gilbert 1882), with a disjunct distribution from Bahia Magdalena,
Baja California Sur (BCS) and Golfo de California to northern Nayarit, México,
and from Costa Rica to Peru; (2) L. piguitinga (Schreiner and Miranda-Ribeiro
1903) which inhabits the fresh and brackish waters of the Atlantic drainage of
Venezuela and Brazil; and (3) L. gracilis Castro-Aguirre and Vivero 1990, known
from Jalisco, México to Golfo de Fonseca, Honduras.

Methods

All body measurements and counts of fin rays, gill rakers, ventral scutes, and
midlateral scales were taken based on Whitehead’s methods (1985). Original mor-
phometric data were transformed to thousandths of the cephalic length or standard
length and descriptive statistics (mean, standard deviation, mode, and range) were
computed. An analysis of discriminant function (Statistica 4.2 program) was used
to identify the most important biometric characters to classify Lile nigrofasciata
and L. stolifera.

D, SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

Fig. 1. Holotype of Lile nigrofasciata (CI: 2032), adult female, 104 mm SL, Bahia de Guasimas,
Sonora, México. Photograph by Gorgonio Ruiz-Campos.

Abbreviations of the fish collections where the studied specimens are deposited
are as follows: CI, Centro Interdisciplinario de Ciencias Marinas (CICIMAR,
I.PN.), La Paz, BCS; UABC, Facultad de Ciencias, Universidad Aut6noma de
Baja California, Ensenada, Baja California; ENCB-I.P.N., Departamento de Zool-
ogia, Escuela Nacional de Ciencias Biolégicas, México, D.E; CIB, Centro de
Investigaciones Bioldgicas del Noroeste, S.C., La Paz, BCS; IBUNAM, National
Fish Collection at the Instituto de Biologia, Universidad Nacional Aut6noma de
México, México, D.E; CAS, California Academy of Sciences, San Francisco,
California, U.S.A.; and LACM, Natural History Museum of Los Angeles County,
Los Angeles, California (cf. Other material examined in Appendix 1). Number of
specimens examined is indicated in parenthesis.

Results

Lile nigrofasciata sp. nov. (Fig. 1).

Holotype.—ClI: 2032, a female of 104 mm standard length (SL) from Bahia de
Guasimas, Sonora, México, collected by E.E Balart and A. Arreola Lizarraga, 23
Feb. 1996, at a depth of 1.5 m.

Paratypes.—CI: 2039 (1), 98 mm SL collected along with the holotype; IBUN-
AM: P9520 (2), 96.0-100.0 mm SL, idem; CIB: 3001 (2), 93.1-94.5 mm SL,
idem. CI: 1886 (50), 56.5—77 mm SL, Santispac, Bahia Concepcién, BCS, col-
lected by PJ.P. Whitehead, 29 Nov. 1988. CI: 4922 (35), 74.1-86.0 mm SL, Estero
El Conchalito, Ensenada de La Paz, BCS, México, collected by A.E Gonzdélez-
Acosta, 18 Aug. 1997.

The results of the morphometric and meristic analysis are listed in the Table 1.

Diagnosis.—A species belonging to the genus Lile, with the following differ-
ential characteristics: body elongate, very compressed and high, its maximum
depth 3.3 to 4.4 (mean = 3.7) times in standard length; dorsal and ventral profiles
convex; 36 to 40 (mode = 38) gill rakers on lower limb of the first gill arch; 34

A NEW SPECIES OF LILE OF THE EASTERN TROPICAL PACIFIC 3

to 49 (mode = 40) midlateral scales; 14-18 (mode = 16) prepelvic scutes; 10—
16 (mode = 12) postpelvic scutes; dorsal and anal fins with 13—17 (mode = 15)
and 14—16 (mode = 16) rays, respectively; head relatively small, its maximum
length 3.7 to 5.4 (mean = 4.2) times in standard length; body with a dark green
(in life) or black (in alcohol) band extended from the supraposterior edge of the
opercle to the final part of the caudal peduncle; iris black; pupil translucent,
whitish or lightly gray; most of individuals examined have both tips of their
caudal lobes with a black stain; color of the opercle in specimens <70 mm SL
is gray-silver, and in those >80 mm SL with a dark gray or black stain.
Description.—Body elongate, fusiform, compressed, with dorsal profile arched
and the ventral profile notably convex. Cephalic region spindle-shaped; mouth
oblique, almost vertical. Head relatively small, its length 3.7 to 5.4 (mean = 4.2)
times in standard length; eye large, its diameter 2.4 to 4.1 (mean = 3.0) times in
cephalic length; preorbital distance shorter than eye diameter and contained 3.1
to 5.2 (mean = 3.9) times in cephalic length; postorbital distance longer than eye
diameter and contained 1.9 to 3.2 (mean = 2.6) times in cephalic length. Posterior
edge of opercle rounded and flat, not serrated, but with a concave notch on its
post-distal part. Preopercle flat, its posterior edge straight, shallowly oblique and
directed anteriorly where it connects with the rounded suborbital. A distinctive
membranous structure on anterior edge of cleithrum that appears juxtaposed to
first lateral scales, and covered with a great number of highly ramified complex
tubules. Tubular system extended to nuchal region where it connects to other side
of body by means of a tubular system. Two anterior fontanels located between
supraocular and nuchal regions, distinguishable as two dark areas, also identified
as a complex tubular system connected with those of the preopercle, opercle, and
membranous structure. Mouth terminal, protrusible, forming a tubular structure
composed of two supramaxillary bones, which are associated with the maxillary
bone. Both sides of symphysis of lower jaw with several series of conical, blunt,
minute teeth. Inner border of jaws without teeth; conical and unicuspidated teeth
forming a conglomerate on the palatines. Tongue spatulate and lacking teeth. Six
branchiostegal rays supported by flexible ligaments. Lower limb of the first gill
arch with 36 to 40 (mode = 38) thin elongate gill rakers, closely approximated.
The pseudobranch has from 13 to 14 relatively thick filaments. Body elongate,
compressed, deep, maximum depth 3.3 to 4.4 (mean = 3.7) times in standard
length; dorsal profile arched, ventral profile notably convex. The ventral scutes
originate from the first scale behind the isthmus and finish before the anal pore;
their numbers range from 14 to 18 (mode = 16) prepelvic and 10 to 16 (mode
= 12) postpelvic or preanal. Origin of dorsal fin situated before that of the pelvic
fins and closer to tip of mouth than to base of caudal peduncle. Dorsal fin length
is almost equal to the cephalic length; dorsal rays from 13 to 17 (mode = 15),
the last two rays highly ramified. Pectoral fins relatively small, falciform, their
length almost equal as the cephalic length; insertion of pelvic fins begins at post-
distal part of gill opening and above the thoracic border. Pelvic fins small, their
maximum length 1.6 to 2.5 (mean = 1.9) times in cephalic length, and 8 branched
rays. Anal fin short, not very high, with a scaly sheat, and 14 to 16 rays (mode
= 16), the last two rays branched; anal fin situated at posterior one-third of the
body. Caudal fin forked, 5-11 upper procurrent rays, 10 upper principal rays (9
of them forked), 9 lower principal rays (8 of them forked), and 6—9 lower pro-

4 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

Root 1 vs. Root 2

4 = ee —
6 L
Bt Oo
Oo oO
4 | Bes periph
o ae ao o 00
3 oo, oh 0°20 0
7a lal 220 89 Qa,
ie)
ee ; o eee) 9f o8 1e)
= O (e\2)
8 0} A
or Po
-4 | oe © = eee ae
i iS SS x OL. nigrofasciata
2 6 Oo ne “fe y A Bahia Concepcion BCS
-3 o8 3 eo PN ae OL. stolifera
os nN Bahia Concepcién BCS
-4 00% A a
© —L. stolifera
5 El Conchalito BCS
6 ee : i : ce 4 _L. nigrofasciata
10 8 6 a 2 0 2 4 6 8 El Conchalito BCS

Root 1

Fig. 2. Discriminant function analysis of populations of Lile spp. in the Gulf of California, México.
Axis | vs. Axis 2. Pooled data.

current rays. Scales large, somewhat deciduous, with smooth border, four contin-
uous grooves and one discontinuous of central position, the nearest groove to the
lower border has the form of an arch, the other cross the entire scale. Number of
scales in lateral series varies from 34 to 49 (mode = 40); predorsal scales 11—
13. Total vertebrate 40—41 (mode = 41), 14 or 15 (mode = 15) caudal. Predorsal
bones (=upperneurals) between cranium and the first dorsal finrays 9—11 (mode
= 11). Caudal complex with two (60%) or three (40%) epurals.

Biometric Analysis.—Twenty-one biometric variables of 85 examined speci-
mens of Lile nigrofasciata and 71 L. stolifera were analyzed. Wilks’ Lambda
values varied from 0.0027 to 0.0204, suggesting a strong discrimination between
the species (Wilk’s Lambda for all variables combined: 0.00273, approx. F (63, 304)
= 39.010, p < 0.0000). The values of tolerance ranged between 0.4974 and
0.9002. The classification matrix obtained here indicates that 100% of the ex-
amined individuals were correctly classified for the populations of Lile nigrofas-
ciata (Bahia Concepcion and El Conchalito, BCS), as well as that of L. stolifera
from El Conchalito, BCS. The specimens of L. stolifera from Bahia Concepcion
were correctly classified with an accuracy of 97.22%.

Only three of the 21 biometric variables analyzed contributed significantly to
the discrimination of both species of Lile: interorbital distance (p < 0.00001),
number of midlateral scales (p < 0.00003), and number of gill rakers on the lower
limb of the first gill arch (p < 0.00000).

The squared Mahalanobis distances were significantly greater between popu-
lations of L. nigrofasciata and L. stolifera, but were not significant between pop-
ulations of the same species, as shown in the graph of the discriminant function
analysis (Fig. 2).

AGNEW SPECIES OF LILE OF THE EASTERN TROPICAL PACIFIC 3)

Coloration.—Living specimens, with the exception of the olive-green or black
midlateral band, are yellowish-green and somewhat translucent in their predorsal
region. The head is also yellowish-green, with a gray-silver spot on the preopercle
and opercle as result of a great concentration of black pigment inside the branchial
chamber. Gums and distal part of the lower jaw are black. The upper lip and
internasal area are black or dark gray. The gill filaments are whitish or yellowish.
The oral chamber is whitish. A distinctive black or dark line travels from the
nape to the dorsal fin origin and to the precaudal area. The iris is black or dark
gray, the pupil is whitish and translucent. In most individuals both caudal lobes
are tipped black, although some of them have only the upper lobe with a faint
black tip. Anal, pectoral, and pelvic fins are yellowish or whitish.

Habitat.—The holotype and five paratypes were caught in 1.5 m in Bahia de
Guasimas, Sonora, near the town of the same name. This coastal lagoon, with
anti-estuarine circulation and muddy-sandy bottom, is located at the geographical
coordinates, 27°54’ and 27°59’ N, and 110°48’ and 110°55’ W. Water conditions
at capture were: salinity, 45 ppt (annual range for 1996, 35—45 ppt), temperature,
20.5°C (annual range for 1996, 14—30°C), and Secchi disc visibility, 0.72 m. The
dominant fish species at the type locality were Ariopsis seemani, Anchovia ma-
crolepidota, Mugil cephalus, Diapterus peruvianus, Anchoa spp., Eucinostomus
spp., and Colpichthys regis. The other paratypes from Bahia Concepcion and
Ensenada de La Paz (Manglar El Conchalito), BCS, were collected in shallow
littoral areas with soft silt, and were usually associated with mangrove roots that
border these coastal lagoons. The fish communities at both BCS sites were rep-
resented by the following dominant species: Eucinostomus spp., Diapterus pe-
ruvianus, Anchovia macrolepidota, Mugil cephalus and Lile stolifera. In addition,
voucher specimens captured at oligohaline conditions (5.0—15 ppt) in the coastal
lagoon of Tres Palos, Guerrero, México, were also examined. Other specimens of
the new species were collected in the Oriental, Occidental, Inferior and Superior
coastal lagoons, Oaxaca, as well as in the Mar Muerto, Chiapas, in salinities of
=35.5 %o. In these last five localities the fish composition is very similar, but Lile
gracilis replaces to L. stolifera.

Etymology: The name nigrofasciata alludes to the obvious dark or black band
that travels the midlateral part of the body, from the posterior edge of the oper-
culum to the end of the caudal peduncle.

Key to the species of Lile of the eastern tropical Pacific

1. Midlateral band dark or black green; iris black; pupil translucent, dark
gray or black; 36—40 (mode = 38) gill rakers on lower limb of the first

Peering. ois ik wettest ene Lile nigrofasciata (Fig. 3A).
Midlateral band silvery; iris yellow or golden-silvery; pupil black, not
translucent; 24—32 gill rakers on lower limb of the first gill arch ........ D

2. Origin of dorsal fin located ahead of or on a vertical through the insertion
of the pelvic fins; 27—42 midlateral scales in a longitudinal series; ventral
profile notably convex; body depth 2.8—3.7 times in standard length; tips of
both caudal lobes with conspicuous black blotches ... Lile stolifera (Fig. 3B).
Origin of the dorsal fin located behind the insertion of the pelvic fins; 34—
36 midlateral scales in a longitudinal series; ventral profile slightly convex

6 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

Fig. 3. Comparison of the three species of the genus Lile of the Eastern Tropical Pacific. (A) Lile
nigrofasciata sp. nov. (holotype, CI: 2032, 104 mm SL), Bahia de Gudsimas, Sonora. (B) Lile stolifera
(CI: 4738, 83 mm SL), Manglar El Conchalito, Baja California Sur. (C) Lile gracilis (ENCB-IPN:
7134, 71.4 mm SL), Mouth of Rio Balsas, Guerrero. Photograph by Gorgonio Ruiz-Campos.

or straight; body depth 4.0—5.5 times in standard length; only the upper tip,
if any, of the caudal fin with a faint dark mark ....... Lile gracilis Figs, see

Geographical distribution.—Based on material examined deposited in the ich-
thyological collections previously mentioned, Lile nigrofasciata is distributed in
the Bahia Magdalena-Bahia Almejas lagoon complex in the southwestern Baja
California Sur, México, the Golfo de California (Bahia de Gudsimas, Sonora;
Bahia Concepcié6n and Manglar El Conchalito at Ensenada de La Paz, BCS), and
along the western coast of Mexico and Central America, to Colombia, Ecuador
and northern Peru.

Discussion

The recognition of this new species is interesting from a systematic and bio-
geographic point of view. Its closest relationship is with Lile stolifera, based on

A NEW SPECIES OF LILE OF THE EASTERN TROPICAL PACIFIC |

the position of the dorsal fin in relation to that of the pelvic fins, both species
having the origin of the dorsal fin ahead of the insertion of the pelvics. This
characteristic is also observed in the Atlantic species L. piquitinga (distributed
from Venezuela to Brazil) but not in L. gracilis (distributed from the central
Pacific of México to Honduras) whose individuals have the dorsal fin origin slight-
ly behind the origin of pelvic fins (Castro-Aguirre and Vivero 1990). L. stolifera
and L. nigrofasciata are distinguished by gill-raker numbers on the lower limb of
the first gill arch, the first species with 24 to 31 (mode = 27), the second with
36 to 40 (mode = 38).

The size and form of the scales also different; L. stolifera has small scales
(average maximum length 3 mm) in the form of a shield with their posterior
edges smoothly convex; in contrast, the scales of L. nigrofasciata measure on
average 5 mm in maximum length, and their posterior edges are angular with the
sharp tips. The most conspicuous diagnostic characteristic is coloration; L. stoli-
fera has a brilliant silvery midlateral band, golden-yellow or silvery-golden iris,
black (no translucent) pupil. In comparison, L. nigrofasciata has a dark or black-
green midlateral band, dark or black gray iris, and the translucent gray pupil. Both
species share characters such as the numbers of scales in a longitudinal series,
ventral scutes, and anal rays (Table 1), and filaments of the pseudobranch (12 to
14). Based on five cleared-and-stained specimens of both species, a preliminary
osteological study revealed some interesting facts: whereas the total vertebrae
number are almost the same in L. stolifera and L. nigrofasciata (41—42 vs. 40—
41), the caudal vertebrae number is not. L. stolifera has 16 to 17 (16) caudal
vertebrae and L. nigrofasciata has 14 to 15 (15). On the other hand, L. gracilis
has 38 to 40 (38) total vertebrae number and 17 to 18 (17) caudal vertebrae
number. In comparison, the Atlantic species L. piquitinga, has 38 to 41 total
vertebrae and 14 to 15 caudal vertebrae (GOmez-Gaspar 1976). L. stolifera has 8
to 10 (9) predorsal bones, L. nigrofasciata 9 to 11 (11), and L. gracilis 8 to 9
(9), very near to L. stolifera, but the first bone of the series is larger than in the
other species (Fig. 4). L. piquitinga has 7 to 8 predorsal bones (G6mez-Gaspar
1976; McGowan and Berry 1984). Two or three epural bones were observed in
the caudal skeleton of L. nigrofasciata (Fig. 5), whereas in L. stolifera two epural
bones is the most frequent situation (80%) and rarely three. Vivero and Romero-
Castillo (1990) found two epural bones in L. gracilis; however, in very small
specimens (e.g. 35.6 mm) three epural bones can be observed; in some the double
character of the second epural bone is still evident. Some osteological studies
have shown that in some species of Clupeiformes the fusion of one pair of epural
bones is relatively common during larval development (Balart 1985; Matsuoka
1938):

The geographical ranges of both species also differ (Fig. 6): Lile nigrofasciata
has a widespread distribution in the eastern tropical Pacific, while L. stolifera has
a quasi-antitropical distribution. Both species are sympatric from Bahia Magda-
lena-Bahia Almejas coastal lagoon complex in the northwestern Baja California
Sur and both coasts of Golfo de California to Bahia Banderas, Jalisco, México.
The distribution of Lile stolifera is interrupted from northern Bahia Banderas,
appearing again as sympatric with L. nigrofasciata from Costa Rica to Pert (Cas-
tro-Aguirre et al. 1999). L. nigrofasciata is also sympatric with L. gracilis from

g SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

Fig. 4. Characteristic arrangement of predorsal bones (left lateral view) in Pacific species of Lile.
(A) L. nigrofasciata sp. nov., (B) L. stolifera and (C) L. gracilis. cr, cranium; ns, neural spine; pd,
predorsal bone; pr, proximal radial of dorsal fin support.

the Mexican central Pacific to Golfo de Fonseca, Honduras (S. Contreras-Bald-
eras, unpublished data).

Photographs of specimens identified as “‘Lile stolifera’”’ that were provided by
Chirichigno (1963: 14, fig. 5) and Yafiez-Arancibia (“‘1978”’ [1980]: 266, plate
12, fig. 4) correspond to L. nigrofasciata.

It is not feasible to present a probable phylogeny of the genus because more
detailed anatomical studies of the four nominal species are needed, particularly
the osteology of the caudal complex and the neurocranium, as well as a compar-
ative study of their early ontogenic stages. Based on some osteologic aspects of
Lile gracilis, Vivero and Romero-Castillo (1990) proposed that the allopatrical
processes led to the persistence of neotenic characters. It is necessary, however,

as

Fig. 5. Comparison of the caudal skeleton (left lateral view) of the three species of the genus Lile
in the eastern tropical Pacific. (A) L. nigrofasciata sp. nov., (B) L. stolifera and (C) L. gracilis. a,
radial cartilage; cp, preural centrum; e, epural; h, hypural; na, neural modified spine; 0, opisthural
cartilage; ph, parhypural; u, ural centrum; un, uroneural. Stippled areas, cartilage.

SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

10

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A NEW SPECIES OF LILE OF THE EASTERN TROPICAL PACIFIC 11

Pacific : Atlantic
Ocean

oD
SSS
SOS S,

E = L. piquitinga
(fll L. gracilis

IS) L. stolifera
=58

nigrofasciata

Fig. 6. Distribution ranges of the species of the genus Lile in tropical America.

to carry out finer studies to understand the evolutionary processes that gave origin
to L. gracilis, the species that replaces L. stolifera in the central part of the tropical
eastern Pacific.

Acknowledgments

We wish to thank the following persons and institutions for the facilities and
assistance provided during the present study: José De La Cruz-Agiiero and Adrian
Gonzalez-Acosta from Ichthyological Collection of CICIMAR-IPN, for providing
help during the examination of specimens utilized in the description of this new
species. Liduvina Pérezgomez from Laboratory of Morphophysiology (CICI-
MAR-IPN), for assisting in the process of clearing and staining of the specimens
utilized in the osteological analysis. CIBNOR’s Arachnology & Entomology Lab-
oratory for providing the camera lucida for drawing the fish bone sketches and
to the Ichthyological Collection of CIBNOR for providing part of the type ma-
terial supporting this study. Oscar Armendariz (CIBNOR) for making the final
edition of the fish bone drawings. William N. Eschmeyer and Tomio Iwamoto
from the Department of Ichthyology of the California Academy of Sciences in
San Francisco for the loan of specimens for this study. Jeffrey A. Seigel from the
Natural History Museum of Los Angeles County, in Los Angeles for the access
to database and specimens. Salvador Contreras-Balderas from Bioconservacion
A.C., in Monterrey (México) for providing the southernmost record of L. gracilis.
Daniel A. Guthrie and two anonymous reviewers provided useful comments and
editorial help on the manuscript. Finally, Faustino Camarena-Rosales (UABC) for
assisting in the statistical analysis of morphometric data.

Literature Cited

Balart, EE 1985. Development of the vertebral column, fins and fin supports in the Japanese anchovy,
Engraulis japonicus (Clupeiformes, Engraulididae). Bull. Mar. Sci., 56: 495—522.

12 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

Castro-Aguirre, J.L., and J.M. Vivero. 1990. Existencia de una nueva especie del género Lile Jordan
y Evermann (Osteichthyes: Clupeidae) en la costa occidental del Pacifico mexicano. An. Esc.
Nac. Cien. Biol., México, 33: 135-146.

Castro-Aguirre, J.L., H. Espinosa Pérez, and J.J. Schmitter-Soto. 1999. Ictiofauna estuarino-lagunar y
vicaria de México. Noriega-Limusa, México, D.E 711 pp.

Chirichigno EK, N. 1963. Estudio de la fauna ictiol6gica de los esteros y parte baja de los rios del
Departamento de Tumbes [Perti]. Servicio de Pesquerias, Pert, Ser. Divul. Cient., 22: 1-87.

Gomez-Gaspar, A. 1976. Osteologia de Lile piquitinga (Schreiner and Miranda-Ribeiro 1903) (Pisces:
Clupeidae). Bol. Mus. Mar, Univ. de Bogota, 8: 3-52.

Matsuoka, M. 1998. Osteological development in the Pacific sardine, Sardinops melanostictus. Ich-
thyol. Res., 44: 275-295.

McGowan, M.F, and FH. Berry. 1984. Clupeiformes: development and relationship. Pp. 108—126. Jn:
Moser, H.G., W.J. Richards, D.M. Cohen, M.P. Fahay, A.W. Kendall, Jr., and S.L. Richardson
(eds.). Ontogeny and Systematics of Fishes. American Society of Ichthyologist and Herpetol-
ogist, Special Publication No. 1.

Vivero, J.M., and J. Romero-Castillo. 1990. Lile gracilis Castro-Aguirre y Vivero: un caso de espe-
ciaci6n por neotenia. Bol. Inst. Oceanogr. Venezuela, Univ. de Oriente, 28 (1—2): 121-126.

Whitehead, PJ.P. 1985. FAO species catalogue. Vol. 7. Clupeoid fishes of the world. An annotated
and illustrated catalogue of the herrings, sardines, pilchards, sprats, anchovies and wolfherrings.
Part |. -Chirocentridae, Clupeidae and Pristigasteridae. FAO Fisheries Synopsis (125), Vol. 7,
Pel xc e082

Yanez-Arancibia, A. “1978” (1980). Taxonomia, ecologia y estructura de las comunidades de peces
en lagunas costeras con bocas efimeras del Pacifico de México. Centro Cien. Mar y Limnol.,
Univ. Nac. Auton. México, Publ. Esp., 2: 1-306.

Accepted for publication 16 March 2001

Appendix |. Other Material Examined:

Lile nigrofasciata sp. nov. Baja California Sur, México: Ensenada de La Paz at Manglar [Estero de]
El Conchalito, Cl: 4954, 30(57.5—85.0 mm), 16-17/LX/1997, A.E Gonzalez Acosta; Bahia Magdalena
at Estero San Buto [24° 46’ N, 112° 05’ W], CI: 4560, 1(110.0 mm), 4/VI/1984, coll.?; Bahia Mag-
dalena at Estero Las Botellas [24° 26’ N, 111° 07’ W], CI: 778, 1(77.0 mm), 10/XI/1985, U. McGregor;
Bahia Magdalena at Estero San Carlos [24° 47’ N, 112° 05’ W], CI: 2279, 2(77.0-78.0 mm), 8/XI/
1990, R. Rodriguez; Bahia Magdalena at Puerto Chale [24° 43’ N, 111° 32’ W], CI: 1861, 1(98.3
mm), 14/1V/1986, FE Garcia; Bahia Magdalena at Estero Médano Amarillo [24° 43’ N, 112° 02’ W],
CI: 1894, 4(87.0—96.0 mm), 11/11/1981, J.L. Castro Ortiz. Guerrero, México: Laguna de Tres Palos
[15° 48’ N, 98° 46’ W], CI: 2282, 63(33.0—61.0 mm), 24/IV/1991, PJ.P. Whitehead et al. Tumaco,
Colombia, CAS: 213293, 20 (49.0—82.5 mm), 1913, A. Henn & C. Wilson.

Lile stolifera. Baja California Sur, México: Ensenada de La Paz at Manglar El Conchalito, CI: 4738,
7(79.0-86.0 mm), 22-23/IV/1997, A.E Gonzalez Acosta; Estero de San José del Cabo [22° 55’ N,
109° 46’ W], CI: 3279, 58 (56.0—71.0 mm), 17/V/1989, PJ.P. Whitehead & R. Rodriguez; Bahia San
Juanico at Punta Pequeha, LACM: 32084, 73 (45-64 mm), 28/X/1971, C. Swift; Bahia Concepcién
at Isla Anegada, CI: 1011, 36(53.0-74.0 mm SL), 12/VIII/1990, J. Rodriguez et al.; Rio Santa Rosalia
[=San Luciano], LACM: 50296, 4 (47—62 mm), 12/III/1957, G.W. Barlow; Rio Mulegé at 2.1—3.0
km above the mouth, UABC: 0180, 2(47.7—61.7 mm), UABC: 0191, 3(46.2—50.7 mm), UABC: 0204,
1(47.7 mm), 14/X/1995, G. Ruiz-Campos. Nayarit, México: Estero San Blas, LACM: 50485, 1(86
mm), 30/1/1958, B.W. Walker et al. Puerto Parker, Costa Rica, CAS: 146862, 10(54.0—73.5 mm), 12-
22/1/1938, W. Beebe et al.

Lile gracilis. Guerrero, México: Mouth of the Rio Balsas (La Barra de San Francisquito), ENCB-IPN:
7134, 6(53.0-74.0 mm), 24/11/1988, A. Marmolejo; and Rio Balsas at Brazo de San Francisquito,
CIB: 2501, 5(35.6—67.6 mm), 6/X/1993, E de Lachica-Bonilla et al.

Bull. Southern California Acad. Sci.
101(1), 2002, pp. 13-23
© Southern California Academy of Sciences, 2002

Food habits of the spotted sand bass Paralabrax maculatofasciatus
(Steindachner, 1868) from Laguna Ojo de Liebre, B.C.S., Mexico

Noemi Bocanegra-Castillo,! L. Andrés Abitia-Cardenas,! Victor H. Cruz-
Escalona,’ Felipe Galvan-Magana,' and Lucia Campos-Davila’
'Departamento de Pesquertas y Biologia Marina, Centro Interdisciplinario de
Ciencias Marinas, Apartado Postal 592, La Paz, Baja California Sur, México
LP 000=elephones 4-92 (112) 253244, Fax>. 52) (112) 253-22, E-mail:
labitia @ redipn.ipn.mx
*Divisién de Biologia Marina, Centro de Investigaciones Biolégicas del
Noroeste, S. C., Apartado Postal 128, La Paz, Baja California Sur,
México 23000

Abstract.—Feeding habits of spotted sand bass Paralabrax maculatofasciatus, in
Laguna Ojo de Liebre, B.C.S., Mexico, were analyzed. According to relative
importance index the amphipod Corophium spp., isopod Paracerceis spp., poly-
chaetes Pherusa spp., crabs Callinectes bellicosus and fish were the most impor-
tant items. Seasonal variations were observed during May-September, Corophium
spp. and Paracerseis spp. were the most important prey, whereas C. bellicosus
and fish were important during November. The smaller spotted sand bass fed
mainly on amphipods, isopods and mollusks, whereas the largest bass fed on crabs
and Octopus spp. No trophic overlap was found between size-intervals of spotted
sand bass. We concluded that P. maculatofasciatus are carnivorous predators that
feed mainly on epibenthic invertebrates.

Resumen.—Se analizaron los habitos alimentarios de la cabrilla arenera Parala-
brax maculatofasciatus, en Laguna Ojo de Liebre, B.C.S., México. Las presas
mas importantes fueron: el anfipodos Corophium spp., isopodos Paracerceis spp..,
poliquetos Pherusa spp., jaibas Callinectes bellicosus y peces. Se observaron
variaciones temporales en el espectro de la cabrilla arenera. Las presas mas im-
portantes en Mayo-Septiembre fueron: Corophium spp. y Paracerceis spp; mien-
tras que en Noviembre fueron C. bellicosus y peces. Las cabrillas mas pequejfias
se alimentan principalmente de anffpodos, isopodos y micromoluscos; mientras
que las mas grandes se alimentan de C. bellicosus, peces y Octopus spp. No hubo
traslapamiento trdfico entre las clases de talla de cabrilla arenera. Se concluyo
que la cabrilla arenera es un depredador bent6nico que tiene un espectro alimen-
tario muy diverso el cual esta compuesto de pequefos invertebrados y peces.

Members of the Serranidae (sea basses) inhabit tropical and temperate areas in
the continental shelf, from the shallows to moderate depths. A total 47 species
(18 genera) of sea bass occur in the central, eastern Pacific (Heemstra 1995). One
of these species is the spotted sand bass, Paralabrax maculatofasciatus, which is
distributed from San Francisco Bay, California to Guerrero, Mexico, including
the Gulf of California (Miller and Lea 1972; Heemstra 1995).

The spotted sand bass is one of the most important demersal species in north-
western Mexico. However, in spite of their abundance, it is not considered im-

{3

14 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

. Las Bombas

. La Hielerita

. El Datil

. Isla Brosa

. Isla Piedra

. Las Dunitas

. La Ensenadita

. Canal de Ballenas

rae. . Campo Ejidatario

- 10. La Concha

414° 20° W ag ae 114° 00’

Fig. 1. Study area. Laguna Ojo de Liebre, B.C.S., Mexico and sampling sites.

portant in fisheries (Lluch 1995). The spotted sand bass is a highly dominant
permanent species in Laguna Ojo de Liebre, Baja California Sur, Mexico (Fig.
1). This geographical area is included in an ecological reserve named “*La Reserva
de la Biosfera El Vizcaino,’ which is the largest reserve in Mexico and one of
the biggest of the world.

Several studies on feeding habits of the spotted sand bass have been done
(Navarro 1985; Diaz and Soto 1988; Ferry et al. 1997; Mendoza and Rosales
2000), but not within Laguna Ojo de Liebre. Studies of the food habits of dom-
inant fish in coastal environments are very helpful for defining the ecological
relationships of these organisms with the rest of the community. Our study ex-
amined the: 1) seasonal changes in the feeding habits of spotted sand bass; and
2) ontogenetic shifts in diet based on stomach content analysis.

Material and Methods

Fish were collected in four samplings (May, July, September, and November
1995) with gill nets 140-m long, 3-m wide, and a mesh size of 9 cm. The nets
were set in 10 sampling locations of the lagoon (Fig. 1). The nets were set at

FOOD HABITS OF PARALABRAX MACULATOFASCIATUS 15

sunset (18:00) and recovered at sunrise (06:00). To reduce the digestive processes,
the abdominal cavities of bass were injected with a solution of 10% formaldehyde
neutralized with sodium borate.

In the laboratory, the prey items were identified to the lowest possible taxo-
nomic level and recorded quantitatively, by number (N), weight (W) and fre-
quency of occurrence (FO) (Hyslop 1980). The average weight and number of
each item prey were determined. The Index of Relative Importance (IRI) of Pinkas
et al. (1971) was used to determine the overall importance of each prey type. This
index can also be expressed as a percentage, with higher values indicating higher
importance.

IRI = (W + N)FO

where IRI = index of relative importance, W = percent weight, N = percent
number, and FO = percent frequency of occurrence.

Plots of cumulative prey diversity in gut contents were calculated to find the
appropriate sample size by length-class and season. The sample size was consid-
ered adequate when the curve reached a horizontal asymptote (Hoffman 1978;
Remy et al. 1997).

The percentage contributions by IRI of the various dietary categories in the
diets of individuals from different intervals (9.9—13, 13.1—16, 16.1—19 mm etc)
were calculated.

The prey diversity in the diet is an estimation of dietary breadth (Marshall and
Elliot 1997) and was calculated using Levin’s standardized index (Krebs 1998):

BS hia = nf(u/s Ps} - 1

where Bi = Levin’s index for the predator i, P;, = proportion of prey / in the diet
of predator 7, and n = the number of prey categories. This index ranges from 0
to 1; low values (<0.6) indicate a diet dominated by few prey items (specialist
predator) and higher values (>0.6) indicate generalist diets (Krebs 1998; Labro-
poulou and Eleftheriou 1997).

The diet overlap between the different size-classes of spotted sand bass by
season was calculated using Morisita’s index (Krebs 1998):

OCheD~S(@RaPy) = (3 ea Ps]

where CX = Morisita’s index of predators i and k, and Pky = proportions of
predator i and k with prey 7 in their stomachs. Diet overlap increases as the
Morisita’s index increases from 0 to 1. Overlap is generally considered biologi-
cally significant when the value exceeds 0.60 (Langton 1982).

Results

Spotted sand bass were caught during May, July, September, and November.
This species is widely distributed in the lagoon mainly in sandy and muddy
bottoms (Acevedo 1998). A total of 151 fish were caught with an average standard
length (SL) of 17.35 cm + 5.16 cm (standard deviation) and an average weight

16 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

i <=
Do
S
=
2)
—
a
~~
=
oO)
—
>
®
—_
a.
>
=
wn
—
o)
—
OQ

58 Tf
Stomach number

Fig. 2. Randomized cumulative prey curve for all fish with gut contents analyzed.

of 97.8 g + 11.9. Of the total stomachs analyzed, 109 contained food (72%) and
42 were empty (28%).

The 109 stomachs with food were sufficient to describe global spectrum of the
spotted sand bass according to the methodology proposed by Hoffman (1978) and
Ferry et al. (1997). We used the same strategy to determine the sample size by
season (except in November, because we sampled only two stomachs) and by size
intervals. All the subsamples were representative of the spotted sand bass diet
(Fig=2).

Thirty-three food components were identified. Benthic invertebrates dominated
the diet of spotted sand bass. By number of organisms, 53% were amphipods
(Corophium spp.) 17% isopods (Paracerceis spp.), and 7%. polychaetes (Pherusa
spp.). The rest of the food components had low values (<5%) (Fig. 3). The
average number of food components in each stomach was 2.5 = 5.

The most important prey by weight was the warrior swimcrab Callinectes bel-
licosus (30%), followed by the fish Hypsoblennius spp. (17%), the amphipods
Corophium spp. (10%) and polychaetes Pherusa spp. (9%). The amphipods Cor-
ophium spp. (46%), the polychaetes Pherusa spp. (29%) and the isopods Para-
cerceis spp. (28%) dominated in frequency of percentage occurrence (Fig. 3).

According to IRI, amphipods Corophium spp. (66%), isopods Paracerceis spp.
(12%), polychaetes Pherusa spp. (11%) and warrior swimcrab C. bellicosus (5%)
were the most important food components (Table 1).

Relative importance of several prey varied seasonally (Fig. 4). During May,
July, and September (spring-summer), the amphipods Corophium spp., the isopods
Paracerceis spp. and the polychaetes Pherusa spp. were the most common in-
vertebrates in the diet. In November (winter), the warrior swimcrab, the fish Hyp-
soblennius spp., the Octopus spp. and Nassarius spp. were the most important
prey.

We analyzed five size-classes (9.9—-34.6 cm SL) with intervals of 3.0 cm. In

FOOD HABITS OF PARALABRAX MACULATOFASCIATUS 17

—
®
Q
E
=|
re
(2
®
3)
=
®
QE

1 Anfipoda 5 Fishes

2 Isopoda 6 Other mollusk
3 Polychaeta 7 Gastropoda

4 Decapoda

Percent weight

26.8

34.4 21.8

8.4
Percent frequency of ocurrence

Fig. 3. The major prey species found in the stomach of spotted sand bass Paralabrax maculato-
fasciatus presented as percent of number of individuals, weight, frequency of occurrence, and index
of relative importance.

the diet of spotted sand bass, the prey with reduced mobility, such as the benthic
amphipods and gastropods, were more common in the diet of the small fish (<25
cm SL). The largest spotted sand bass (>25 cm SL) feed on larger prey with
faster movements such as warrior swimcrab and fish (Fig. 5).

The low values of Levin’s index (Bi) by each size category (between O to 0.52),
indicated that spotted sand bass could be categorized as specialist in their feeding
habits. The small and large spotted sand bass had higher specialization degree
and the medium size had a lower specialization degree (Fig. 6).

In global analysis, dietary overlap values between size classes were high. The
most evident were between the size classes 1—2 (A = 0.85), 1—4 (A = 0.86), 2—
3 (A = 0.83), 2-4 (A = 0.84). However, in seasonal analyses we don’t find sig-
nificant evidence for dietary overlap (values less than 60%) according to meth-
odology’s Langton (1982).

Discussion

We found a considerable number of food components within the trophic spec-
trum of the spotted sand bass (33 food components). However few prey of the
benthic habitat were dominant within their diet. Ferry et al. (1997) also noted that
spotted sand bass, like many other serranids, is a generalist feeder. Other studies
have recorded that decapods and fish were the major components in the diet of
the spotted sand bass (Navarro 1985; Diaz and Soto 1988; Cruz-Escalona 1998).

18 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

Table 1. Summary of food categories in stomach contents of spotted sand bass from Laguna Ojo
de Liebre, B.C.S., Mexico, expressed as percentages based on number (%N), weight (%W), frequency
of occurrence (FO) and index of relative importance (IRI).

Prey JN JoW %FO %IRI
Crustacea
Callinectes bellicosus 1.41 SNe 7 6.42 4.76
Sicyonia spp. 0.85 1.88 326i) 0.23
Penaeus spp. eT! 0.32 6.42 0.23
Solenocera spp. 0.14 O53) 0.92 0.01
Squilla spp. 0.28 0.01 0.92 0.01
Majidae 0.14 0.09 0.92 <0.001
Corophium spp. Sieg KO P28) 45.87 64.65
Califanthura spp. 0.56 0.02 1.83 0.02
Paracerceis spp. 16.78 1.82 28.44 12.00
Cirolana spp. 4.37 0.53 OAT 1202
Shrimp (unidentifiable). 0.14 0.15 0.92 0.01
Brachyuran crabs (unidentifiable) 1.83 0.07 5.00 0.16
Crustacean remains (unidentifiable) 0.14 3163 11:93 1.02
Pignogonida 0.14 0.02 0.92 <0.001
Anellida
Pherusa spp. TENS O22 29°36 10:93
Mollusca
Polyplacophora ZZ 0.22 10.09 O53
Pelecypoda 2.54 4.31 14.68 228
Nassarius spp. jes es: Ori 350 0.20
Fisurella spp. 1.41 0.82 O92 0.05
Solemya valvulus 0.42 0.40 D4 (5) 0.05
Tagelus spp. 0.14 0.89 0.92 0.02
Octopus spp. 0.28 De) 1.83 0.10
Bivalve remains (unidentifiable) 0.28 0.53 1283 0.03
Mollusca remains (unidentifiable) 0.14 1.03 1.83 0.05
Osteichthyes
Hypsoblennius spp. 0.14 W733 0.92 0.36
Gerreidae 0.14 4.09 0.92 0.09
Diplectrum spp. 0.28 0.73 1.83 0.04
Ilypnus gilberti 0.14 0.54 0.92 0.01
Syngnathus leptorhynchus 0.14 0.05 0.92 <0.001
Fish remains (unidentifiable) 113 122 Zeid 0.15
Echinodermata
Ophiactis savignyi 0.14 0.01 0.92 <0.001
Other items 2.26 Dre! 5.50 0.95

Spotted sand bass are distributed widely in Laguna Ojo de Liebre; however
they are most abundant in areas with eelgrass (Zoostera marina). In this environ-
ment, the presence of isopods, amphipods, and mollusks are common (Orth 1977;
Main 1985; Dielh 1992). These groups, not surprisingly, turned out to be the most
important components in the trophic spectrum of the spotted sand bass. Larger
size prey such as the warrior swimcrab C. bellicosus and fish that were important
to larger spotted sand bass are also found in these eelgrass beds.

The high incidence of benthic prey in the diet of P. maculatofasciatus also has

FOOD HABITS OF PARALABRAX MACULATOFASCIATUS 19

Table 2. Diet overlap between size-classes of spotted sand bass Paralabrax maculatofasciatus from
Laguna Ojo de Liebre, B.C.S., Mexico.

Size-class (9.9—-13) Gist l—16) (16.1—19) (19.1—22) G225i)
May
(9.9-13) l
(13.1—16) 0.40 l
(16.1—19) 0.24 0.17 l
(19.1—22) 0.36 0.15 oO} l
e221) 0.05 0.02 0.16 0.05 l
July
(9.9-13) |
(13.1—16) 0.29 l
(16.1-19) 0.03 0.07 |
(19.1—22) Ope 0.05 0.00 l
(22.1) 0.29 0.59 6.00 O32 l
September
(9.9-13) l
(13.1—16) 0) l
(16.1-19) 0.05 0) l
(19.1—22) 0 0 0 l
ec.) 0) 0) 0) 0) l
November
(9.9-13) l
(13.1—-16) 0) l
(16.1—19) 0 0) l
(19.1—22) 0) 0) 0) l
C221) 0) 0) 0) 0) l

been reported in other localities. Mendoza and Rosales (2000) indicated that the
spotted sand bass at Punta Banda, Baja California feed basically on amphipods,
isopods, and fish. However in a seasonal analysis he found that the dominance
of the amphipod Corophium spp. is higher during summer, whereas in winter, the
fish Atherinops affinis and Sardinops sagax were the most important.

In Laguna Ojo de Liebre spotted sand bass also showed seasonal dietary chang-
es; during May—September feeding mainly on small prey, and in November fed
on larger prey. Other authors (Ferry et al. 1997; Cruz-Escalona 1998) also have
reported these seasonal variations. It is presumed that this change is because of
seasonal changes in the availability of prey.

Our analysis of different size classes indicated that spotted sand bass change
diet ontogenetically. Less mobile prey, including benthic amphipods, isopods, and
polychaetes, were proportionately more important in the diet of small spotted sand
bass, suggesting that smaller fish are less capable of catching more mobile prey.
Roberts et al. (1984) noted that mysids and amphipods were more dominant in
the diet of the smaller (<240 mm) barred sand basses Paralabrax nebulifer. How-
ever, they also found that prey such as gastropods and polychaetes were most
abundant in larger barred sand bass.

The ontogenetic changes in the diet represent ecological mechanisms, and re-
flect the low ability of small predators to efficiently capture certain prey (Chao

20 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

~<
if
Q
<
WwW
=
kK
<<
=
mm
o
WwW
O
CE
~
le
oc
O
a
=

JUL
(SUMMER) (WINTER)

[_] Corophium spp E4) Pherusa spp Callinectes bellicosus
EI Mollusca Paracerceis spp E33 Gerreidae

E94 Hippocamphus ingens [A Hypsoblennius spp Hl Octopus spp

(ill Nassarius spp MM Other items

Fig. 4. Seasonal variation of the major prey species in the diet of spotted sand bass Paralabrax
maculatofasciatus determined by index of relative importance (IRI).

ssssees
EEA

Ae oie

IMPORTANCE RELATIVE INDEX

SIZE-CLASS

L_]Corophium spp Pherusa spp Callinectes bellicosus
Paracerceis spp Other mollusk Fisurella spp
Fishes {ll Cirolana spp WM Other items

Fig. 5. Percentage contribution of the most important food item for index of relative importance
of the gut contents found in 151 Paralabrax maculatofasciatus individuals collected. Each bar rep-
resent a fish size class.

FOOD HABITS OF PARALABRAX MACULATOFASCIATUS 21

Breadth diet

=
®
a
=
=)
(=
ic
)
©
=
fo)
_—
n

HT IV
Size class

Fig. 6. Diet breadth of Paralabrax maculatofasciatus according to Levin’s index.

and Musick 1977; Sumpton and Greenwood 1990). In many situations the smaller
fish had not developed certain physical mechanisms (ability to break calcareous
structures) or physiological (enzymatic processes) to feed adequately on some
prey with high availability (Gerking 1994).

We found that spotted sand bass present two feeding behaviors; small and large
fish have a specialization behavior, while the medium size spotted sand bass had
a generalist strategy. Spotted sand bass, as other serranids, possess structures
useful to catch and process a wide diversity of prey items (Pickett and Pawson
1994). Ferry et al. (1997) found a sharply toothed premaxilla, mandible, vomer,
and palatine, as well as fine-toothed gill arches and pharyngeal jaws. This might
explain the wide prey spectrum found in different-sized spotted sand bass. Gerk-
ing (1994), defined this capacity of change as “‘trophic plasticity.”’

The low values of overlap between successive length classes of P. maculato-
fasciatus attest to the gradual changes in diet of this species throughout their life.
The high prey diversity in the diet of spotted sand bass would explain the lower
overlap values obtained. Wootton (1990) indicates that changes by age in the use
of habitat is an important factor in the food preference of each fish species,
because the age implies a food or habitat partitioning between several size-classes
from the same species.

Acknowledgments

The institutional and financial support for this study was provided by the In-
stituto Politécnico Nacional (PIFI and COFAA) and Consejo Nacional de Ciencia
y Tecnologia. Special thanks to Larry Allen for value comments. C. Turren, and
J. EK Elorduy who helping us in some statistical analysis. Also we would like to

92) SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

thanks to anonymous reviewers. Our thanks to E. Glazier for editing the English-
language text.

Literature Cited

Acevedo, C. A. 1997. Caracterizaci6n ecol6gica de la comunidad ictica de la Laguna Ojo de Liebre,
B.C.S., México. Master Sc. Thesis. Centro Interdisciplinario de Ciencias Marinas, Instituto
Politécnico Nacional. 108 pp.

Chao, L. N. and J. A. Musick. 1977. Life history, feeding habits and functional morphology of juvenile
sciaenid fishes the York River estuary, Virginia. Fish. Bull. 75:657—702.

Cruz-Escalona, V. H. 1998. Analisis tr6fico de la ictiofauna en Laguna San Ignacio, B.C.S., México.
Master Sc. Thesis. Centro Interdisciplinario de Ciencias Marinas, Instituto Politécnico Nacional.
129" pp:

Diaz, G. G. and L. A. Soto. 1988. Habitos alimenticios de peces depredadores del sistema lagunar
Huizache-Caimanero, Sinaloa, México Instituto de Ciencias del Mar y Limnologia. Universidad
Nacional Autonoma de México. 15:97—124.

Diehl, S. 1992. Fish predation and benthic community structure: The role of omnivores and habitat
complexity. Ecology, 73(5):1646—1661.

Ferry, L. A., Clark, S. L. and Cailliet, G. M. 1997. Food habits of spotted sand bass (Paralabrax
maculatofasciatus, Serranidae) from Bahia de Los Angeles, Baja California. Bull. So. Calif.
Acad. Sci., 96(1):1—21.

Gerking, S. D. 1994. Feeding ecology of fish. Academic Press, New York. 416 pp.

Heemstra, P. C. 1995. Serranidae. 1565—1613 pp. Jn: Fischer, W., Krupp, FE, Schneider, W., Sommer,
C., Carpenter, K. E. and Niem, V. H. (1995). Guia FAO para la identificaci6n de especies para
los fines de la pesca Pacifico centro-oriental. Vol. II y III. Vertebrados, parte 2.

Hoffman, M. 1978. The use of Pielou’s method to determine sample size in food studies, 56—61 pp.
In: Fish food habits studies. Proc. 2nd Pac. NW Technical. Workshop. Washington Sea Gran
Publications. University of Washington, Seattle.

Hyslop, E. J. 1980. Stomach contents analysis—a review of methods and their application. J. Fish
Biol. 17:411—429.

Krebs, C. J. 1998. Ecological methodology. Harper and Row, New York, 550 pp.

Labropoulou, M. and A. Eleftheriou. 1997. The foraging ecology of two pairs of congeneric demersal
fish species: importance of morphological characteristics in prey selection. J. Fish Biol. 50:
324-340.

Langton, R. W. 1982. Diet overlap between the Atlantic cod Gadus morhua, silver hake, Merluccius
bilinearis and fifteen other northwest Atlantic finfish. U.S. National Marine Fisheries Service.
Fish. Bull. 80:745—759.

Lluch, C. D. B. 1995. Aspectos reproductivos de la cabrilla arenera, Paralabrax maculatofasciatus
(Pisces:Serranidae) en Bahia Magdalena-Almejas, Baja California Sur, México. Master Sc. The-
sis. Centro Interdisciplinario de Ciencias Marinas, Instituto Politécnico Nacional, 145 pp.

Main, L. K. (1985). The influence of prey indentity and size on selection of prey for two marine
fishes. J. Exp. Mar. Biol. Ecol., 88:145—152.

Marshall, S., and M. Elliot. 1997. A comparasion of univariate and multivariate numerical and graph-
ical techniques for determining inter- and intraspecific feeding relationships in estuarine fish. J.
Fish. Biol., 51:526—545.

Mendoza, C. M. and J. A. Rosales. 2000. The feeding habits of spotted sand bass (Paralabrax ma-
culatofaciatus) in Punta Banda Estuary, Ensenada, Baja California, Mexico. CALCOFI Reports,
41:194—200.

Miller, J. D., and R. N. Lea. 1972. Guide to the coastal marine fishes of California. Calif. Dep. Fish
and Game, Fish Bull., 157: 259pp.

Navarro, M. M. 1985. Ecologia tréfica de la comunidad ictica en el Estero de Punta Banda, Ensenada,
México. Master Sc. Thesis. Centro de Investigaci6n Cientifica y de Educacién Superior de
Ensenada. 185 pp.

Orth, R. J. 1977. The importance of sediment stability in seagrass communities. 281—300 pp. Jn: B.C.
Coull (ed.) Ecology of marine benthos. University of South Carolina Press.

Pickett, G. D. and M. G. Pawson. 1994. Sea Bass: biology; explotation, and conservation. Chapman
and Hall, New York, 337 pp.

FOOD HABITS OF PARALABRAX MACULATOFASCIATUS 28

Pinkas, L., M. S. Oliphant and I. L. K. Iverson. 1971. Food habits of Albacore, bluefin Tuna and
Bonito in California waters. State of California. The resources agency. Department of fishes
and game. Fish Bull., 152: 105 pp.

Roberts, D. A., E. E. De Martinini, and K. M. Plummer. 1984. The feeding habits of juvenile-small
adult barred sand bass (Paralabrax nebulifer) in nearshores waters off northern San Diego
Country. CalCOFI Rep. XX V:105—111.

Sumpton, W., and J. Greenwood. 1990. Pre and post-flood feeding ecology of four species of juvenile
fish from the Logan Albert estuarine system, Moreton Bay, Queensland. Aust. J. Mar. Fresh.
Res., 41:795—806.

Wootton, R. J. 1990. Ecology of teleost fishes. Champan and Hall, London, 404 pp.

Accepted for publication 21 December 2000.

Bull. Southern California Acad. Sci.
101(1), 2002, pp. 24—27
© Southern California Academy of Sciences, 2002

First Specimens of the Fangjaw Eel Echiophis brunneus (Pisces:
Ophichthidae) from the Gulf of California, México

Gorgonio Ruiz-Campos! and José Luis Castro-Aguirre?

'Facultad de Ciencias, Universidad Autonoma de Baja California, Apdo. Postal
1653, Ensenada, Baja California, 22800, México. U.S. Mailing: PMB # 064,
P.O. Box 189003-064, Coronado, California 92178. E-mail:
gruiz@ bahia.ens.uabc.mx
*Departamento de Pesquerias y Biologia Marina, Centro Interdisciplinario de
Ciencias Marinas, Instituto Politécnico Nacional. Apdo. Postal 592, La Paz,
Baja California Sur, 23000, México

The fangjaw eel was first referred to by McCosker (1977) as an undescribed
ophichthid species of the genus Echiophis Kaup 1856, with a potential distribution
from the Gulf of California to Panama. Castro-Aguirre and Suarez de los Cobos
(1983) described this ophichthid fish as a new genus and species (Notophtophis
brunneus) on the basis of a specimen collected in Bahia de Acapulco, Guerrero,
México. McCosker et al. (1989) reassigned this new taxon into the known genus
Echiophis, which contains five nominal species in the Atlantic and one or two
species in the eastern Pacific.

Echiophis brunneus (Castro-Aguirre & Suarez de los Cobos 1983), also known
as “Pacific spoon-nose eel,’ is a benthic fish that reaches 1.4 m in length and
inhabits shallow coastal waters with sandy and muddy bottoms (McCosker and
Rosenblatt 1995). Although many bio-ecological aspects of this species are un-
known, it is commonly found in the stomach contents of scalloped hammerhead,
Sphyrna lewini, from southern Sinaloa (J.L. Castro-Aguirre, pers. obs.).

The northernmost collection report of E. brunneus in the vicinity of the mouth
of Rio Presidio, southern Sinaloa, México (Amezcua-Linares 1996) is considered
invalid, because it was based on an erroneous identification of specimens of Cy-
noponticus coniceps (Castro-Aguirre et al. 1999). Therefore, the presence of E.
brunneus in the Gulf of California has not been previously confirmed with vouch-
er specimens.

Two specimens of E. brunneus (Fig. 1) were captured with a commercial
shrimp net on 19 January 1999 near El Desemboque, Sonora, between Santo
Tomas and Cabo Tepoca, upper Gulf of California (30° 34’ N, 113° O01’ W). Both
specimens were taken at a depth of 33 m on a sandy bottom. Our specimens of
E. brunneus confirm the occurrence of this ophichthid eel in the Sea of Cortez
zoogeographical province (sensu Briggs 1974; Thomson et al. 2000).

The specimens of fangjaw eel were identified using the following combination
of diagnostic characteristics (Castro-Aguirre and Suarez de los Cobos 1983; Allen
and Robertson 1994): body elongated, cylindrical, pointed at both ends; tail longer
than head and trunk; pectoral fins present; gill opening relatively elongate, vertical
and lateral; snout short, subconical, slightly constricted near tip; teeth very strong
and pointed, biserial, largest anteriorly on jaws; body overall tan with abundant
small, brown spots on back and sides; and dorsal fin brown. A very large canine

24

FANGJAW EEL IN THE GULF OF CALIFORNIA 2S

Aaa Seer hey ate Cet a gar ee rt

\ “Stik
§ COE Sara Dems 7
a ey ae ey le BN -y,

ae
i

Fig. 1. A) Fangjaw eel, Echiophis brunneus, UABC-0960, 995 mm TL, collected in El Desem-
boque, Gulf of California, México, on 19 January 1999. B) Lateral view of the head region of the
Same specimen. Photographs by Gorgonio Ruiz-Campos.

26 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

tooth inserted on the distal part of the vomer is considered diagnostic for specific
identification; however, one of the examined specimens showed two canine teeth.

Morphometry of the two collected specimens was based on Castro-Aguirre and
Suarez de los Cobos (1983). The body measurements in millimeters of the two
specimens are as follows: total length (TL) (862 and 995); distance from tip of
snout to: origin of anal fin (425 and 428), anus (418 and 422), origin of dorsal
fin (152 and 155), axilla of pectoral fin (114 and 115), and gill opening (102 and
101); maximum head width (42.4 and 43.7), maximum head depth (44.7 and
42.0), width of mouth (32.7 and 35.7), maxillar length (53.6 and 52.8), mandible
length (52.1 and 52.4), snout length (15.4 and 13.9), maximum interorbital width
(13.2 and 14.4), minimum interorbital width (11.2 and 10.7), horizontal ocular
diameter (8.8 and 9.3), distance from tip of snout to anterior (10.7 and 9.8) and
posterior nostril (12.8 and 10.9), and internostril space (2.7 and 2.3).

The coloration of the specimens as preserved in alcohol is dark brown on back,
and light brown below. Faint reticulations and small black round spots spread
along the dorsum and sides of the trunk and tail. The dorsal fin base has a black
margin, and the mouth cavity is white-cream and pinkish on the pharyngeal re-
gion.

The specimens are deposited in the Fish Collections of the Facultad de Ciencias,
Universidad Autonoma de Baja California (UABC-0960) and Centro Interdisci-
plinario de Ciencias Marinas, Instituto Politécnico Nacional (CICIMAR-CI 4793).

Acknowledgments

We thank Eric Mellink Bijtel from Centro de Investigaci6n Cientifica y de
Educacion Superior de Ensenada (CICESE) for providing the specimens of fa-
ngjaw eel. We also thank the Los Angeles County Museum of Natural History
(LACM), National Museum of Natural History (USNM), Scripps Institution of
Oceanography (SIO), the California Academy of Sciences (CAS), and the Instituto
de Biologia of the Universidad Nacional Aut6noma de México (IB-UNAM) for
consulting their fish collections and data bases. Daniel A. Guthrie and two anon-
ymous reviewers made useful comments on the manuscript.

Literature Cited

Allen, G.R. and D.R. Robertson, 1994. Fishes of the tropical eastern Pacific. University of Hawaii
Press, Honolulu. 332 pp.

Amezcua-Linares, E 1996. Peces demersales de la plataforma continental del Pacifico Central de
México. Instituto de Ciencias del Mar y Limnologia, Universidad Nacional Aut6noma de México
& Comisi6n Nacional para el Conocimiento y Uso de la Biodiversidad, México, D.F 184 pp.

Briggs, J.C. 1974. Marine zoogeography. McGraw-Hill, New York. 475 pp.

Castro-Aguirre, J.L., and S. Suarez de los Cobos. 1983. Notophtophis brunneus, nuevo género y
especie de la familia Ophichthidae, (Pisces: Angnilliformes [sic]) hallado en la Bahia de Aca-
pulco, Guerrero, México. Anales de la Escuela Nacional de Ciencias Biologicas, México, 27:
113-128.

Castro-Aguirre, J.L., E.E Balart, and H. Espinosa Pérez. 1999. Revision critica del libro denominado:
‘““Peces demersales de la plataforma continental del Pacifico central de México’’, por Felipe
Amezcua Linares. México: Instituto de Ciencias del Mar y Limnologia, UNAM/CONABIO,
184 pp., 1996. Revista Zoologia Informa, 1999(42):11—16.

McCosker, J.E. 1977. The osteology, classification, and relationships of the eel family Ophichthidae.
Proc. Calif. Acad. Sci., series 4, 41(1):1-123.

McCosker, J.E., E.B. Bohlke, and J.E. Bohike. 1989. Family Ophichthidae. In: Bohlke, E.B. (ed.),

FANGJAW EEL IN THE GULF OF CALIFORNIA jail

Vol. I: Order Anguilliformes and Saccopharyngiformes. Fishes of the Western North Atlantic.
Sears Foundation for Marine Research, 1(9):254—412.

McCosker, J.E., and R.H. Rosenblatt. 1995. Ophichthidae. In: Fischer, W., EK Krupp, W. Schneider, C.
Sommer, K.E. Carpenter, and V.H. Niem (eds.). Guia FAO para la identificaci6n de especies
para los fines de la pesca. Pacifico centro-oriental. Volume HI. FAO, Rome, Italy.

Thomson, D.A., L.T. Findley, and A.N. Kerstitch. 2000. Reef fishes of the Sea of Cortez. The Uni-
versity of Texas Press, Austin. 353 pp.

Accepted for publication 13 March 2001.

Bull. Southern California Acad. Sci.
101(1), 2002, pp. 28-35
© Southern California Academy of Sciences, 2002

Observations on nesting seabirds and insular rodents in the Middle
Sea of Cortes in 1999 and 2000

Eric Mellink, Adriana Orozco-Meyer, Beatriz Contreras, and
Monica Gonzalez-Jaramillo.

Centro de Investigacion Cientifica y de Educaci6n Superior de Ensenada, B.C.
Carretera Tijuana-Ensenada Km 107. Ensenada, B.C.

The Sea of Cortés has been touted as an area of great biological diversity.
However, much of the information on the biota of this area comes from single
visits, often several. decades old, and frequently the data is transmitted only ver-
bally or in a generic sense. Regretably, although a number of scientists conduct
research in the area, little information has been published. As a result, our ability
to determine the temporal or spatial changes in the populations of the native
species of this area, and the negative impacts of human activities is limited.

General survey data of homeotherms helps to document and understand chang-
es in size of populations or shifts in their distribution, and can be especially
important when the most recent published data is at least several decades old. In
this spirit we present our observations from three cruises to the Middle Sea of
Cortés in 1999 and 2000.

These cruises were 5—17 April 1999, 19-30 October 1999, and 6-19 April
2000, and were made aboard the Enchantress, a 49-ft Florida ketch, under the
sponsorship of The Kelton Foundation. The locations visited are shown in figure
1, and the intineraries were:

April 1999: La Paz, Los Islotes, Isla Partida (Ensenada Grande), Isla San José
(Punta Colorada), Puerto del Gato, Timbabichi, Isla Monserrat (SW end), Isla
Carmen (Punta Baja), San Juanico, San Hdefonso, Farallon de San Ignacio, Isla
Cerralvo, Isla Espiritu Santo (El Candelero), La Paz.

October 1999: La Paz, Isla San Francisco, Isla Habana, Isla Morena, Roca
Negra, Puerto del Gato, Roca Marcial, Montserrat, Isla Las Galeras, Puerto Es-
condido, Isla Los Coronados, Bahia Siquicismunde, Isla San Ildefonso, Bahia
Coyote, Isla Santa Inés, Isla Tortuga, Santa Rosalia.

April 2000: La Paz, Roca Marcial, Isla Cholla, Los Coronado, San Juanico,
San Ildefonso, Bahia de Santo Domingo, Bahia Coyote, Punta Chivato, San Mar-
cos (southern tip), Santa Rosalia, Tortuga, San Pedro Martir, Bahia San Pedro,
San Pedro Nolasco, San Carlos, Farall6n de San Ignacio, Espiritu Santo, La Paz.

During these cruises we made observations on all homeotherms encountered;
we surveyed several islands used for breeding by seabirds, and set rodent traps
on 5 islands. Most navigation was diurnal, and we carried out observations
throughout the day. On those occasions that navigation was nocturnal we made
few observations. Herein we report on the nesting seabirds and insular rodents.
Our objective in this note is to provide our data, rather than make detailed anal-
ysis, and we restrict literature coverage to a minimum.

28

VERTEBRATES OF THE MIDDLE SEA OF CORTES 29

Mar de Cortés

La Paz

Isla Cerralvo

Isla Espiritu Santo
Isla Partida

Los Islotes

Isla San Francisco
Isla San José

Isla Habana

Isla Morena

10 Roca Negra

11 Timbabichi

12 Puerto del Gato

13 Roca San Marcial

14 Isla Monserrat

15 Islas las Galeras

16 Puerto Escondido

17 IslaCarmen

18 Isla Cholla

19 Isla Coronados

20 San Juanico

21 Bahia Saquiscismunde
22 Isla San Ildefonso

23 Bahia Coyote

24 Bahia Santo Domingo
25 Isla Santa Inés

26 Punta Chivato

27 Isla San Marcos

28 Santa Rosalia

29 Isla Tortuga

30 Isla San Pedro Martir
31 Isla San Pedro Nolasco
32 Bahia San Pedro

33 Puerto San Carlos

34 Farall6n de San Ignacio

1
2
3
4
5
6
i
8
9

Fig. 1. Central and southern Sea of Cortés showing the locations mentioned in the text.

30 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

Table 1. Nesting localities of nesting seabirds in the Sea of Cortés in April 1999 and 2000. A *‘X”’
represents confirmed nesting, ““?”’ possible nesting, ““No” (in San Ildefonso) the notable lack of this
former species’ colony.

Magnifi- Red- Double-
cent billed Blue- crested Heer- Yellow-
Frigate- Tropic- Brown Brown’ footed Cormo- mann’s legged
bird bird Pelican Booby Booby rant Gull Gull

Cerralvo xX

Ballena xX

Gallo

Gallina

Roca Monumento

Los Islotes xX

Las Animas xX

Roca San Marcial ye
Roca Solitaria

San Damian

Monserrat

Las Galeras (both)

Isla Cholla

Unnamed, SW Coronado

San Ildefonso x »4 xX No

ee a a oe a a

Bahia Coyote
Guapa
Blanca
Pitaya
San Ramon xX
Liebre
Coyote + its rocks
Tecomate
San Marcos
Tortuga
San Pedro Matrir xX
San Pedro Nolasco &
Farallon de San Ignacio xX

xx x
TKK KKK MK KK

x KK XK
xy KM

Sea Birds

On small islands or restricted populations where we could count all nests (or
adults sitting on nests) without disturbing the birds, we did so. Brown pelicans
are very sensitive to human intrusion, and, therefore, even on small islands we
did not count them. On large islands we obtained counts or estimates on the
minimum number of nesting pairs. Our counts of larger colonies from the vessel
are likely to have been very limited. We did not search for crevice-nesting birds,
so except for the Red-tailed Tropicbird, we restricted ourselves to seabirds that
nest on the surface. The summary of nesting species per island is presented in
table 1. The species accounts follow:

Fregata magnificens. Magnificent Frigatebird.

This species was common throughout the area covered on all three cruises, but
only in April 2000 did we observe some individuals that could be nesting. On
San Pedro Nolasco there were about 50 on a bush, including some males with

VERTEBRATES OF THE MIDDLE SEA OF CORTES 3]

evident gular pouch. We did not land on the island to verify whether they were
nesting.

Phaethon aethereus. Red-billed Tropicbird.

In April 1999 we saw at least 12 flying over Farallon de San Ignacio. This
species had not been reported to nest on this island (Everett and Anderson 1991),
but was recently documented to do so in large numbers (Gonzdlez-Bernal et al.
submitted).

In April 2000 we saw 2 on San Pedro Martir, one of which seemed to be
nesting (laying in a crevice). This island harbors a large nesting population of
this species (Everett and Anderson 1991, Tershy and Breese 1997).

Pelecanus occidentalis. Brown Pelican.

Brown Pelicans nest on many islands in the Sea of Cortés (Everett and An-
derson 1991). In April 1999 we recorded them breeding on Las Animas. (62
nests, but there could be up to 10 more on the NW end), Isla San Ildefonso
(between 1O000—3000 nests), Southern end of the eastern shore of Isla Cerralvo
(a few decidedly on nests, but we were to far away to count them), and Isla
Ballena (several hundreds).

On las Animas one nest had 2 eggs, and one 2 small chicks, whereas in San
Ildefonso the few nests that we examined (with binoculars, from a ridge) con-
tained from eggs to gray-colored juveniles. Nests on the southern end of this
island seemed to have smaller chicks than nests on the western side. On Ballena
there were chicks of all sizes. Those on the western side of the island were
overally larger than those on the eastern side, suggesting that this was the order
of colony formation.

In April 2000 Brown Pelicans were nesting abundantly on San Ildefonso, Tor-
tuga (thousands), San Pedro Martir (at least hundreds; 2000—3000 pairs were
estimated in the early 1990s—Tershy and Breese 1997), San Pedro Nolasco (thou-
sands), and San Ram6n in Bahia Coyote (40 nests). Large chicks were present
on Tortuga and San Pedro Nolasco.

During non-breeding season, in October 1999 pelicans were rather scant, except
in Bahia Coyote, were we saw over 220 (vs. about 150 in the entire rest of the

trip).

Sula leucogaster. Brown Booby.

Isla San Ildefonso has been a traditional nesting ground for this species (Mel-
link 2000), and, in both years there were several hundred nests there, especially
in the SW area of the island, along with nests of blue-footed Boobies. Pairs varied
from building nests to having 50-days old chicks, suggesting the onset of egg-
laying in early-mid January. Several nests had two large chicks. In October 1999
there were less than 100 individuals on San Ildefonso and no breeding evidence.
Three juveniles were still being fed by their mothers. One of the juveniles had
fishing line coming out of its beak.

In April 2000 Brown Boobies nested abundantly on San Pedro Martir, where
there were several thousands, although we thought not as many as the 74,000
pairs estimated in 1990 (Tershy and Breese 1997). There were surprisingly few
on Tortuga and San Pedro Nolasco. On the first of these two islands we counted

32 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

20, on ledges on the southern cliffs (also used by Blue-footed Boobies), 5 of
which sat on nests. On San Pedro Nolasco there were 50—60 individuals, and
only 11 apparently nesting. We did not land to examine these presumed nests.

On Farallon de San Ignacio we estimated “‘thousands”’ in April of both years,
and detailed counts in March 2001 recorded about 1200 pairs nesting (Gonzalez-
Bernal et al. submitted). In 1999 most of them were at the protected eastern face
of the rock, and on the top of the cliff there were several individuals that appeared
to be incubating or tending chicks, but we failed to see any chicks. However, the
sea was too rough for proper observation of the birds. Rough seas also precluded
landing on both occasions. In April 1999 several juveniles were flying in the area,
suggesting that there may have been breeding in the fall.

Sula nebouxii. Blue-footed Booby.

In April 1999 we found Blue-footed Boobies nesting on Los Islotes (2 empty
nests, but a female sitting on one of them, suggesting that laying was about to
start). On Isla San Ildefonso there were several hundred nests, although fewer
than those of Brown Boobies, in the same area of the latter. Individuals varied
from courtship to tending large 50-day chicks, setting the onset of egg-laying in
early-mid January. In October 1999 there were a few hundred adults on San
Ildefonso, and one pair, perhaps two, appeared to perform courtship displays.

In April 2000 this species was nesting at several places; several hundred on
San Ildefonso, thousands on Tortuga, mostly on the southern cliffs where some
were obviously on nests. Many were nesting on San Pedro Martir. Here they had
from eggs to large chicks. There seemed to be much less than the 110,000 pairs
estimated in 1990 (Tershy and Breese 1997). There were several hundreds on San
Pedro Nolasco. Some were sitting on the ground but it was not clear if they were
on nests. During both years there were many flying about Farallon de San Ignacio,
but we could not confirm nesting, although such was confirmed in 2001 (Gon-
zalez-Bernal et al. submitted).

Phalacrocorax auritus. Double-crested Cormorant.

Double-crested Cormorants were noted in small numbers on many places along
the cruise, but breeding evidence was scant. San Ildefonso is a known breeding
locale for this species (Everett and Anderson 1990), but we could not find any
nesting birds in any of the two years (perhaps because of our avoidance of the
areas occupied by nesting pelicans). However, in October 1999 4 out of 7 adults
had nuptial plumes, and one mummified chick confirmed that nesting had occured
on the island during the previous nesting season. In April 2000 they were nesting
on San Pedro Nolasco, where we counted, from the vessel, 15 nests, some of
which held large chicks.

Larus heermannii. Heermann’s Gull.

There was a breeding colony on Roca San Marcial, both years. In April 1999
there were about 500 individuals, including adults and juveniles. They were be-
ginning to nest, and we counted 34 nests with | egg, and 2 with 2 eggs. One pair
was courting. We found twelve nests and 2 adults that had been predated upon;
the adults probably by Peregrine Falcons (Falco peregrinus), a known predator
of the species (Velarde 1993). In April 2000 there were 200 birds, of which 81

VERTEBRATES OF THE MIDDLE SEA OF CORTES 39

were on nests. We examined 17 nests: 12 had 1 egg, and 5 had 2 eggs. Heermann’s
Gulls were absent from this island in October 1999.

Isla San Ildefonso had been a traditional nesting site for this gull (Mellink
2001). However, in April 1999 and April 2000 there was clearly no nesting by
this species (see also Mellink 2001). In April 1999 there were a few dozen birds
at Farall6n de San Ignacio, and in April 2000 we found evidence of their nesting
here. There were between 20 and 40 adults sitting in nesting position on low
rocks off the southeastern edge of the island, and one nest checked from a distance
had eggs (see also Gonzalez-Bernal et al. submitted, and Mellink 2001).

Larus livens. Yellow-legged Gull.

In both years we found this species nesting profusely, or presumed its nesting,
on islands in the area (Table |). In 1999 we examined 109 nests, scattered among
islands along our survey path: 44 contained one egg, 27 two eggs, 36 three eggs,
and 2 four eggs. In 2000 we examined the nests only sufficiently to confirm
nesting, but did not note their contents in detail.

On Las Galeras, in April 1999, on the NW islet the nests were at the western
side. At the NE islet they were on the entire islet, but those at the SW side had
4 eggs. From this area the number of eggs in nests decreased toward the NE side,
where nests had only | egg. This progression suggests the order of colony for-
mation.

On the SE islet of Las Galeras we collected a pile of bones, apparently regur-
gitated. It contained pre-opercula of serranid fishes (Jorge Dominguez, CICESE).
On Isla Cholla there is a fishermen’s hut. As we suspected that fishermen might
have been consuming gull eggs, in April 1999, we examined their trash dump.
We found shells only of domestic fowl’s eggs.

In October 1999 the species was widespread.

Rodents

To survey the rodents, we used Sherman live-traps baited with oat flakes and
natural vainilla extract. A single night in October of 1999, was devoted to each
site. All rodents captured were examined, identified and released on the spot. On
Isla San Ildefonso (80 traps, 25—26 October) and southern Isla Santa Inés (40
traps, 28—29 October) we did not capture any rodents. In no instance did we
capture introduced species.

Isla Los Coronados

We surveyed rodents on Isla Los Coronados on 23-24 October through 40
traps placed in the sandy spit on its southern end, and 40 on the rocky volcanic
outcrops adjacent to it. We trapped two species.

Chaetodipus spinatus pullus. 13 females, 9 males, | unsexed. They occurred
principally in the sand spit, but a few also in the rocky area. Soil workings by
this species in the sand spit were extensive.

Peromyscus pseudocrinitus. 5 females, one of them pregnant, 10 males, | un-
sexed. Unlike Alvarez-Castafieda (1998), who found the species more common
in the sandy area, we found it restricted to the rocky outcrops. It is posible that
a current increase in the population of pocket mouse has caused this restriction.

The trapping success attained in this study contrasts sharply with the findings

34 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

of Smith et al. (1993) who, during 249 night-traps in the southern area (roughly
the same spot we used) caught only | pocket mouse. We did not see any evidence
of current existence of feral cats on the island, although our search effort was
insufficient to address this conclusively.

Coincident with Smith et al.’s findings, there was no sign suggesting that Neo-
toma bunckeri could still be extant, although our efforts were largely insufficient
to address this issue. These authors contended that the extinction of this packrat
had been brought about by the removal of ironwood (Olneya tesota) for fuel, and
the introduction of domestic cats. Based on our experience with packrat ecology
and conservation problems elsewhere, we feel that introduction of cats would
have been sufficient to have caused their demise on this island, and that, in the
absence of cats, the impact of firewood removal would not have been critical to
the packrats.

Isla Tortuga

On 29-30 October, 80 traps were set in the most vegetated area high on the
northwestern section (27°26'34"N, 111°53'41”"W). We trapped one species.

Peromyscus dickeyi. 5 females (1 pregnant, 2 recently lactated, | inactive, 1
juvenile), 2 males (1 with abdominal testes, | juvenile). In 1997 Alvarez-Casta-
neda and Cortés-Calva (1999) had a 9% trapping success of this species; identical
to that found by us. Their trapping location was not given.

Isla Coyote

On Isla Coyote, Bahia Coyote, inside Bahia de Concepcion (27—28 October),
from which no native rodents have been reported, we placed 80 traps on top of
the central ridge of the island. We captured one mouse.

Chaetodipus spinatus, unknown ssp. One postlactant female. There are some
pocket mouse workings in the area were she was caught, but this seem to be the
only suitable area for them on the island. Therefore, the population should be
very reduced.

Acknowledgements

The Kelton Foundation supported our work in the Middle Gulf of California
in 1999 and 2000, aboard the Enchantress. Its crew were: Richard Kelton (Cap-
itain), Robert Chappel, Mary Nicholls-Jereabek and Juana Graciano-Dominguez.
Jorge Dominguez identified fish remains in regurgitates from a Yellow-footed
Gull. To all, of them, our deepest appreciation.

Literature Cited

Alvarez-Castafieda, S.T. 1998. Peromyscus pseudocrinitus. Mammalian Species 601:1—3.

Alvarez-Castafieda, S.T. and P. Cortés-Calva. 1999. Muridae. Pp. 445-570 in S.T. Alvarez-Castafieda
and J.L. Patton, eds., Mamiferos del noroeste de México, CIBNOR, La Paz, B.C.S. México.

Everett, W. T. and D. W. Anderson. 1991. Status and conservation of the breeding seabirds on offshore
Pacific islands of Baja California and the Gulf of California. International Council of Bird
Protection Technical Publication 11:115—139.

Gonzalez-Bernal, M.A., E. Mellink, and J.R. Fong-Mendoza. Submitted. Nesting birds of Farall6n de
San Ignacio, Sinaloa, México. Western Birds.

Mellink, E. 2000. Breeding of Brown Boobies in the Gulf of California: Seasonality and Apparent
Effects of El Nino. Waterbirds 23:89-—99.

VERTEBRATES OF THE MIDDLE SEA OF CORTES 35

Mellink, E. 2001. History and status of colonies of Heermann’s Gull in Mexico. Waterbirds 24:188—
194.

Smith, EA., B.T. Bestelmeyer, J. Biari y M. Strong. 1993. Anthropogenic extinction of the endemic
woodrat, Neotoma bunkeri Burt. Biodiversity Letters 1:149—155.

Tershy, B. R. and D. Breese. 1997. The birds of San Pedro Martir Island, Gulf of California, Mexico.
Western Birds 28:96—107.

Velarde, E. 1993. Predation of nesting larids by Peregrine Falcons at Rasa Island, Gulf of California,
Mexico. Condor 95:706—708.

Accepted for Publication 8 August 2001.

Bull. Southern California Acad. Sci.
101(1), 2002, pp. 36-41
© Southern California Academy of Sciences, 2002

Macroparasites of Pacific sanddab Citharichthys sordidus (Bothidae)
from polluted waters of the Palos Verdes Shelf, southern California

Cheryl C. Hogue and Jeanie M. Paris

Department of Biology, California State University,
Northridge, California 91330-8303

Pacific sanddab Citharichthys sordidus Girard is very abundant along the Pa-
cific coast of North America and is an important food fish in California (Hopkins
1986). It is a major component of trawl-caught fish in many locations in the
Southern California Bight (SCB) (Allen et al. 1999). Pacific sanddab inhabits
polluted waters off the coast of southern California where it associates with bot-
tom sediments that contain a variety of contaminants like dichlorodiphenyltri-
chloroethane (DDT), polychlorinated biphenyls (PCBs), polycyclic aromatic hy-
drocarbons (PAHs) as well as heavy metals (Eganhouse and Venkatesan 1993).

More than a hundred papers have demonstrated a correlation between parasit-
ism and pollution in marine fish (Khan and Thulin 1991). There is an enormous
variation in responses of different parasite taxa to different types of pollution
resulting in increased or decreased parasitism (Mackenzie 1999). Pollutants may
lower resistance of fish to parasites or increase the density of animals that transmit
parasites to fish (Eiras 1987, Khan and Kiceniuk 1988). Decreased parasitism, on
the other hand, can result from direct or indirect toxicity effects on parasites.
Changes in densities of invertebrate hosts can also lead to decreased parasitism
in fish (Lafferty 1997). The fact that environmental changes can affect parasites
in SO many ways suggest that data on parasitized fish that are impacted by pol-
lution may be useful as a more sensitive indicator of changes in aquatic environ-
ments.

Although much is known about the life history of Pacific sanddab (Arora 1951;
Rackowski and Pikitch 1989), little is known about the relationship between pol-
lution and parasitism in this fish host. Previously, Love and Moser (1983) reported
8 parasite species infecting Pacific sanddab. The present study focuses on the
population of Pacific sanddab that occupies the waters off White Point, part of
the Palos Verdes Shelf (PVS). Here the sediments contain high concentrations of
contaminants that can bioaccumulate in the tissues of this fish (McDermott-Ehr-
lich et al. 1978). Historically, the tissues of PVS fishes exhibit some of the highest
levels of DDT in the nation (Mearns et al. 1988). The purpose of this study is to
report on the prevalence and intensity of ecto- and endoparasites of Pacific sand-
dab from the highly polluted waters of the PVS. The effect of seasonality and
host age on parasitism was also examined.

Materials and Methods

A total of 137 Pacific sanddab was obtained from otter trawls of the research
vessel Vantuna (owned and operated by Occidental College, Eagle Rock, Cali-
fornia). Bottom trawls for fish off White Point (33°43'’N, 118°19’W) ranged in
depth from 91 to 110 m. Sanddab were collected during August 1997, October

36

MACROPARASITES OF PACIFIC SANDDAB oy

1997, February 1998, and April 1998. Fish were transported to the laboratory
where they were measured (mm) and otoliths were removed for aging. Otoliths
were either sectioned using the techniques of Love et al. (1984) or sanded, and
visible growth annuli were counted.

Fish samples were preserved using the quick-freezing technique of Bush and
Holmes (1986) and later thawed and necropsied. Organs examined for parasites
were gills, heart, liver, gallbladder, spleen, muscle, and gastrointestinal tract. Par-
asites found were sorted into major taxonomic groups, cleaned, counted, and
fixed. Digenea, Monogenea, Cestoidea, and Acanthocephala were fixed in AFA
(ethyl alcohol-formalin-acetic acid), stained with Semichon’s Carmine, and
mounted in Canada Balsam. Nematoda were fixed in 70% glycerin ethyl! alcohol,
cleared, and examined as temporary mounts in glycerin. Parasitic copepods and
isopods were placed in 70% ethyl alcohol.

Prevalence (proportion of infected individuals in a population), mean intensity
(average number of parasites per infected host), and mean abundance (average
number of parasites per host examined, both infected and uninfected hosts) were
calculated. Chi-square analysis was used to assess the relationship between prev-
alence and season as well as between prevalence and host age for the most com-
mon macroparasites of Pacific sanddab. Parasite intensities were log-transformed
to adjust for skewed distributions and mean parasite intensities were compared
among four seasons (summer and fall 1997 and winter and spring 1998) and three
age classes. Pooling 3 year old and 4 year old fish produced the 3 year old age
class, since few 4 year old sanddabs were collected. The average size of fish in
each of the three age classes was 129 mm (range 97-195 mm) for 1 year old
sanddabs; 132 mm (range 102—220 mm) for 2 year old sanddabs, and 173 mm
(range 109-215 mm) for 3 year old sanddabs. A significance level of P = 0.05
was used for all statistical tests performed.

Voucher specimens of the following parasites found infecting Pacific sanddab
were deposited in the Harold W. Manter Laboratory of Parasitology, University
of Nebraska Lincoln: Anisakis sp. (HWML 16475), Corynosoma sp. (HWML
16474), Lacistorhynchus dollfusi (HWML_ 16472), Naobranchia occidentalis
(HWML 16476), Pseudotagia sp. (HWML 16471), and Sterrhurus magnatestis
(HWML 16473). Specimens of the host, Pacific sanddab, were deposited at the
Natural History Museum of Los Angeles County, Catalog No. 55943-1.

Results and Discussion

Pacific sanddab populations off White Point are infected with 11 species of
macroparasites. Corynosoma sp. Luhe, 1904 (Order Polymorphida), Cucullanus
sp. Mueller, 1777 (Ascaridida), Entobdella hippoglossi (Mueller, 1776) Blainville,
1818 (Dactylogyrida), Lacistorhynchus dollfusi Beveridge and Sakanari, 1987
(Trypanorhyncha), Lironeca ovalis Sey 1818 (Isopoda), and Pseudotagia sp. Ya-
maguti, 1963 (Polyopisthocotylida) represent new host records for Pacific sanddab
(Table 1). The state of maturity of some of the helminths infecting sanddab sug-
gests that this host functions as a final host for Cucullanus sp., Pseudotagia sp.,
and Sterrhurus magnatestis as gravid individuals of these species were found.
Sanddabs probably serve as second intermediate hosts for pleroceroids of tetra-
phyllidean cestodes and L. dollfusi and obtained them by feeding on their first
intermediate host, crustaceans. Corynosoma sp. has an indirect life cycle. Im-

38 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

Table 1. Prevalence, mean intensity, mean abundance, and location of helminths infecting Pacific
sanddab from White Point, Palos Verdes Shelf 1997 to 1998.

Prevalence Mean Mean
(percent) Intensity Abundance
Taxon (# infected) . SE* + SE Location**

Digenea

Sterrhurus magnatestis Ow 10h 1010 “OL052210,027" S, 1
Monogenea

Entobdella hippoglossi*** CG) —- — G

Pseudotagia sp. (10)(14) 18 2 O4AG OFS 2-006" 1G
Cestoidea

Lacistorhynchus dollfusi GSO TOM" == WES AS aged ea M

Tetraphyllidean plerocercoids (2)(3) Z.0F 2 O10 CMOLOL = 1008 1
Nematoda

Anisakis sp. ; Gsayaon 447 = 05 3.6 = 04 “LV. M.S; PC ayn

Cucullanus sp. (20)(28) 2. Deer OIs OG == O52 S; PGS
Acanthocephala

Corynosoma sp. (2)(2) 1-0' ="0:0 0.01 + 0.01 M
Copepoda

Phrixocephalus cincinnatus (2)(2) 1:0, =" O:0 O01 =0:01 Ee

Naobranchia occidentalis COGS) 2-29 036. O62 0.15 16
Isopoda

Lironeca ovalis (7)(9) Peles (Oot O07 210.02" *G

* SE = standard error of the mean.

** Tocation in host: E = eye; G = gill, LV = liver, M = mesentery, S = stomach, PC = pyloric
ceca, I = intestine, MU = muscle.

*5 Only one host was infected with the parasite.

mature stages of this helminth occur in amphipods and fishes. Marine mammals,
like the California sea lion, Zalophus californianus, function as definitive hosts.
Few fish were infected with the parasitic arthropods L. ovalis and Phrixocephalus
cincinnatus (Table 1). Perkins and Gartman (1997) have previously addressed the
usefulness of P. cincinnatus as a biological indicator of water quality. These
authors noted that there appears to be a relationship between the prevalence of
P. cincinnatus and the distance of its host from outfall sites. However, Perkins
and Gartman (1997) found the overall level of infection of sanddabs to be low.
This was also the case in the present study as only 2% of Pacific sanddab on the
PVS were infected with the eye copepod, P. cincinnatus.

Gill copepods (Naobranchia occidentalis), juvenile anisakine nematodes (Ani-
sakis sp.), and plerocercoids of L. dollfusi dominated the infracommunity of Pa-
cific sanddab. The latter two species were often found encysted within the mes-
entery. Prevalence of these macroparasites varied significantly over the seasons
studied. Both Anisakis sp. and L. dollfusi were more prevalent in winter (83%
and 92%, respectively) and spring (89% and 94%, respectively) compared to
summer (58% and 52%, respectively) and fall (54% and 71%, respectively). The
highest prevalence of N. occidentalis was seen in fall (49%) and the lowest in
winter (8%). Only mean intensities of L. dollfusi were significantly different sea-

MACROPARASITES OF PACIFIC SANDDAB 39

20 n=16

Naobranchia
occidentalis

Anisakis sp.

Lacistorhynchus
dollfusi

MEAN INTENSITY
S

yO +

©

SUMMER FALL WINTER SPRING
SEASON

Fig. 1. Seasonal mean intensity of 3 common macroparasites infecting Pacific sanddab from White
Point, Palos Verdes Shelf, during four seasons: summer and fall 1997, and winter and spring 1998. N
is the number of infected hosts per season. Only the mean intensities of L. dollfusi were found to be
significantly different seasonally (F; ,)3;) = 3.08, P = 0.03.

sonally with the highest mean intensity of these parasites occurring in summer
(Fig. 1). Mean intensities of Anisakis sp. and L. dollfusi were also compared
among 3 age classes of sanddab, but no significant differences were seen (for
Anisakis sp. F.., = 0.36, P = 0.70 and for L. dollfusi Fy 5, = 0.16, P = 0.85).

Seasonal changes in prevalence of fish parasites is common (Chubb 1982) and
can be influenced by several factors including temperature and host diet (Williams
and Jones 1994). Although temperature data were not collected at the time sand-
dabs were obtained for this study, this variable can affect the development of
macroparasites like parasitic copepods (Conley and Curtis 1993).

Pacific sanddab, a bothid and demersal fish species, is an opportunistic feeder
(it readily consumes crustaceans, polychaete worms, razor clams, and juvenile
rockfish) that can tolerate disturbed and polluted habitats like that of the PVS
(Cross et al. 1985; Rackowski and Pikitch 1989). Crustaceans, like euphausiids,
can be a substantial component of the diet of sanddabs (Hopkins and Hancock
1980) and euphausiids can serve as intermediate hosts for Anisakis sp. (Smith
and Wootten 1978). Benthic faunal assemblages do vary on the PVS, being in-
fluenced by such things as pollution, El] Nino, and even strong storms (Thompson
et al. 1993). It is possible that seasonal and geographical availability and distri-
bution of crustacean prey could account for differences in the seasonal prevalence
of Anisakis sp. and L. dollfusi in Pacific sanddab.

Although sanddab populations from White Point are infected with 11 different
taxa, the average sanddab host had only 2 parasite taxa. Reduced numbers of
parasite taxa as well as the total number of parasites per host may reflect changes
in intermediate and/or final host population sizes (Overstreet 1997). Further stud-
ies are needed on parasite populations of Pacific sanddab from less polluted areas

40 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

in the SCB to assess their feasibility as a model for tracking pollution exposure
in their host.

We thank Occidental College for the Pacific sanddab samples and James Hogue
for assistance with transport of the fish.

Literature Cited

Arora, H. L. 1951. An investigation of the California sanddab, Citharichthys sordidus (Girard). Cal-
ifornia Fish and Game, 37:2—42.

Allen, M. J., D. Diener, J. Mubarak, S. B. Weisberg, and S. L. Moore. 1999. Demersal Fish assem-
blages of the Mainland Shelf of southern California in 1994. Pp. 101—112 in Southern California
Coastal Water Research Project Annual Report 1997—1998. (S. B. Weisberg, ed.), Reynolds and
Reynolds Santa Ana, California, 210 pp.

Bush, A. O., and J. C. Holmes. 1986. Intestinal helminths of lesser scaup ducks, patterns of association.
Can. J. Zool., 64:132-141.

Chubb, J. C. 1982. Seasonal occurrence of helminths in freshwater fishes. Part IV. Adult Cestoda,
Nematoda and Acanthocephala. Adv. Parasitol., 20:1—292.

Conley, D. C. and M. A. Curtis. 1993. Effects of temperature and photoperiod on the duration of
hatching, swimming, and copepodid survival of the parasitic copepod Salmincola edwardsii.
Can. J. Zool., 71:972—976.

Cross, J. N., J. Roney, and G. S. Kleppel. 1985. Fish food habits along a pollution gradient. Calif.
Fish and Game, 71:28—39.

Eganhouse, R. P. and M. I. Venkatesan. 1993. Chemical oceanography and geochemistry. Pp. 71—189
in Ecology of the Southern California Bight. (M. D. Dailey, D. J. Reish, and J. W. Anderson,
eds.). University of California Press, 926 pp.

Eiras, J. C. 1987. Occurrence of Haemogregarina bigemina (Protozoan: Apicomplexa) in Blennius
pholis (Pisces: Blenniidae) along the Portuguese west coast. J. Fish Biol., 30:597—603.
Hopkins, J. A. 1986. Diel feeding pattern and diet of the Pacific sanddab, Citharichthys sordidus

(Pisces: Bothidae). M. S. Thesis, California State University, Long Beach, 66 pp.

, and M. K. Hancock. 1980. Diel feeding pattern and prey of the Pacific sanddab (Citharichthys
sordidus). Amer. Zool., 20:950.

Khan, R. A. and J. Thulin. 1991. Influence of pollution on parasites of aquatic animals. Adv. Parasitol.,
30:201—238.

, and J. W. Kiceniuk. 1988. Effects of petroleum aromatic hydrocarbons on Monogeneid par-
asitizing Atlantic cod, Gadus morhua L. Bull. Environ. Contam. Toxicol., 41:94—100.

Lafferty, K. D. 1997. Environmental parasitology: What can parasites tell us about human impacts on
the environment? Parasitol. Today, 13:251—255.

Love, M. S., and M. Moser. 1983. A checklist of parasites of California, Oregon, and Washington
marine and estuarine fishes. NOAA Technical Report NMFS SSRF-777. NOAA, Washington,
DaG, 576spp:

Love, M. S., G. E. McGowen, W. Westphal, R. J. Lavenberg, and L. Martin. 1984. Aspects of the life
history and fishery of the white croaker, Genyonemus lineatus (Sciaenidae), off California. Fish.
Bull., 82:179-198.

MacKenzie, K. 1999. Parasites as pollution indicators in marine ecosystems: a proposed early warning
system. Mar. Pollut. Bull., 38:955—959.

Mearns, A. J., M. B. Matta, D. Simecek-Beaty, M. EF Buchman, G. Shigenaka, and W. A. Wert. 1988.
PCB and chlorinated pesticide contamination in U. S. fish and shellfish: a historical assessment
report. NOAA Technical Memorandum NOS DMA 39.

McDermott-Ehrlich, D., D. R. Young, and T. C. Heesen. 1978. DDT and PCB in flatfish around
southern California muncipal outfalls. Chemosphere, 6:453—461.

Overstreet, R. M. 1977. Parasitological data as monitors of environmental health. Parassitologia, 39:
169-175.

Perkins, P. S. and R. Gartman. 1997. Host-parasite relationship of the copepod eye parasite, Phrixo-
cephalus cincinnatus, and Pacific sanddab (Citharichthys sordidus) collected from wastewater
outfall areas. Bull. Southern California Acad. Sci. 96:87—104.

Rackowski, J. P., and E. K. Pikitch. 1989. Specific profiles: life histories and environmental require-
ments of coastal fishes and invertebrates (Pacific Southwest)—Pacific and speckled sanddabs.

MACROPARASITES OF PACIFIC SANDDAB Al

U. S. Fish Wildl. Serv. Biol. Rep. 82 (11.107). U. S. Army Corps of Engineers, TR EL-82-4,
18 pp.

Smith, J. W., and R. Wootten. 1978. Anisakis and anisakiasis. Adv. Parasitol., 16:93—163.

Thompson, B., J. Dixon, S. Schroeter, and D. J. Reish. 1993. Benthic invertebrates. Pp. 369—458 in
Ecology of the Southern California Bight. (M. D. Dailey, D. J. Reish, and J. W. Anderson,
eds.). University of California Press, 926 pp.

Williams, H., and A. Jones. 1994. Parasitic worms of fish. Taylor and Francis, Inc. Bristol, Pennsyl-
vania, 593 pp.

Accepted for publication 21 December 2000

Bull. Southern California Acad. Sci.
101(1), 2002, pp. 42—47
© Southern California Academy of Sciences, 2002

Interactive Effects of Diurnal Period and Seasonality on
Water Potentials of Acacia, and Parasitic and
Autoparasitic Phoradendron

Simon A. Lei

Department of Biology, WDB, Community College of Southern Nevada,
6375 West Charleston Boulevard, Las Vegas, Nevada 89146-1139

Abstract.—Comparative diurnal and seasonal water potentials of Acacia greggii,
and parasitic and autoparasitic Phoradendron californicum were quantitatively
investigated in the Las Vegas Valley of southern Nevada. A perennial P. califor-
nicum plant was autoparasitic on another P. californicum plant, which in turn was
parasitic on an A. greggii host plant. Autoparasitic P. californicum plants had
significantly lower (more negative) diurnal and seasonal water potentials than
parasitic P. californicum plants, which had significantly lower water potentials
than their A. greggii hosts. Water potentials of hosts, parasites, and autoparasites
were significantly lower in midday than predawn hours. All plants were signifi-
cantly more water stressed in the summer than in the spring. Significant interac-
tions were detected between hour of day (diurnal period) and seasonality for water
potentials of A. greggii hosts, and parasitic and autoparasitic P. californicum
plants. Plant water potentials were also significantly correlated with diurnal period
and seasonality, and even more correlated with diurnal/seasonal combination in
southern Nevada.

Phoradendron californicum are perennial, dwarf hemiparasites which once es-
tablished, rely entirely upon their hosts for their supply of water and various
mineral nutrients (Hollinger 1983). Phoradendron californicum plants mainly de-
rive limited resources from their Acacia greggii hosts by direct xylem connection
(Leonard and Hull 1965; Raven 1983; Kaufman 1989). Acacia greggii are hosts
for P. californicum, and these parasites have exploited every conceivable habitat
on their host branches.

Water potentials are more negative in P. californicum tissues than in A. greggil
host tissues (Scholander et al. 1965). Phoradendron californicum-infested trees
had significantly lower (more negative) diurnal and seasonal water potental values
than uninfested trees in southern Nevada (Lei 1999).

Phoradendron californicum plants can be epiparasized by other individuals of
P. californicum, which are in turn growing on A. greggii and Cercidium floridum
host trees (Kuijt 1969; Ehleringer and Schulze 1985; Lei 2000a). However, epi-
parasitism, also known as autoparasitism, occurs infrequently (Ehleringer and
Schulze 1985). Only a limited number of autoparasitic P. californicum individuals
have been found in northwestern Arizona (Ehleringer and Schulze 1985), southern
Nevada, and southeastern California (Lei 2000a and b). The nutrient composition
and infection success of this autoparasite have been documented (Ehleringer and
Schulze 1985; Lei 2000a and b, respectively). Mineral concentrations in autopar-
asites were typically 1.1 to 1.3 times higher than in their parasitic and non-par-

42

WATER POTENTIALS OF HOSTS, PARASITES, AND AUTOPARASITES 43

asitic (C. floridum) hosts (Ehleringer and Schulze 1985). Age and size of A.
greggii hosts are significantly positively correlated with the infection success of
autoparasites (Lei 2000a). Autoparasites had significantly lower canopy area,
flower and fruit production than parasites in southern Nevada (Lei 2000b).

Nevertheless, diurnal and seasonal water potentials of autoparasitic P. califor-
nicum plants have not been quantitatively investigated in southern Nevada. Two
hypotheses were made prior to data collection. First, the ratio of water potentials
for autoparasitic P. californicum plants to parasitic P. californicum plants would
be of similar magnitude as compared to the ratio of water potentials for the
parasitic P. californicum plants to their A. greggii hosts. Second, there would be
interactions and correlations between the diurnal/seasonality combination and leaf
water potentials of hosts, parasites, and autoparasites. These two hypotheses were
tested by field measurements with appropriate statistical analyses.

Materials and Methods
Study Site and Field Measurements

Field studies were conducted within the Las Vegas Valley (36°15'N, 115°00'W;
elevation 770 m) of southern Nevada in March (spring) and July (summer) 2000.
This site, located along the intermittent Tropicana Wash, was chosen based on the
presence of limited autoparasitic P. californicum individuals. The vegetation zone
was dominated by Atriplex spp., with a scattered distribution of Larrea tridentata,
Pluchea sericea, Tamarix ramosissima, and Hymenoclea salsola. The Tropicana
Wash can be rapidly filled with running surface water during and shortly after
major storm events (Lei 1999).

The four seasons are well defined. Summers display desert conditions, with
maximum temperatures usually in the 40°C range. The average annual rainfall is
approximately 105 mm (NOAA, Local climatological data, Las Vegas). Rainy
days average less than one in June to three per month in the winter months.
Occasional summer monsoonal thunderstorms and episodic winter rainfalls are a
major contribution to the total annual precipitation, which can vary considerably
from year to year (Rowlands et al, 1977). Soil erosion, especially along wash
edges, is evidence of the intensity in some of the summer thunderstorm activity.
Winter air temperatures are generally mild and pleasant. Winter rainfalls are mild,
and may last up to several days (Rowlands et al. 1977). A relative humidity of
20 % or less and extremely high evaporation are common in summer seasons
(Lei and Walker 1997a and b).

A total of 16 live autoparasites was found growing on five A. greggii hosts.
All autoparasites found were alive, although portions of some autoparasitic can-
Opies appeared to be dead with no phenophases and with extremely brittle fo-
liages. From casual observations, autoparasites had little or no direct contact with
A. greggii hosts. These autoparasites were found with A. greggii hosts bearing
numerous mature individuals of parasitic P. californicum.

Hosts, parasites, and autoparasites were tagged with a brightly colored yarn
before water potential measurements to facilitate sampling in the same canopies
throughout the day. For each diurnal period, four 10 to 15-cm long terminal shoots
were randomly selected from each tagged plant. Diurnal and seasonal water po-
tentials of hosts, parasites, and autoparasites were obtained using a portable pres-

44 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

Table 1. Diurnal and seasonal water potentials (mean + SE, n = 4 per hour per organism) of A.
greggii hosts, and parasitic and autoparasitic P. californicum plants in the Las Vegas Valley of southern
Nevada.

Water potential (MPa)

Month Hour of day Host Parasite Autoparasite
March 6 1 6.== On = 2.3 0e1 =3.2 30st
9 =e == Ost =2'6°2250.4 —3:6 90n
2 = 292, =O = Oe = sal — 39° On
15 =2.2. 2 OM =310) 70:1 4,007
July 6 2 Si Om F3oesOrl ~4.6°2200
) = 29 Ol Sa 2EION 5:3 e508
12 =o .05=s 0M =p ly O02 —6:4'2)02
15 = 399) OD Sib enO2 6.3) Ue

sure chamber (Plant Moisture Stress Instruments, Corvallis, OR) and nitrogen gas.
Once leaves were incised, they were immediately placed in zip-loc plastic bags
and housed on ice in the dark until pressurization, which was rapidly conducted
at the field site. Diurnal water potentials were measured at predawn (0600 h) and
then at 3-hour intervals through 1500 h. Seasonal water potential data were col-
lected twice, once in March and once in July 2000.

Statistical Analyses

Two-way analysis of variance (ANOVA; Analytical Software 1994) was con-
ducted on water potentials of A. greggii hosts, parasitic and autoparasitic P. cal-
ifornicum plants, with hour of day (diurnal period) and seasonality (March and
July) as main variables. One-way ANOVA, followed by Tukey’s Multiple Com-
parison Test (Analytical Software 1994) was used to detect differences in diurnal
and seasonal water potentials among host, parasites, and autoparasites, and to
compare means when a significant environmental effect was detected, respective-
ly. Linear regression analysis (Analytical Software 1994) was performed to cor-
relate plant water potentials with diurnal period, seasonality, and diurnal/season-
ality combination. Mean values are expressed with standard errors, and P-values
less than or equal to (S) 0.05 are reported as statistically significant.

Results

Diurnal and seasonal water potentials of autoparasitic P. californicum plants
were significantly (P = 0.001) lower compared to parasitic P. californicum plants,
which were significantly lower (P = 0.001) than their A. greggii hosts (Table 1).
Hosts, parasites, and autoparasites revealed a significantly lower midday than
predawn water potential irrespective of seasonality. These plants also exhibited a
significantly lower water potential in the summer than in the spring season re-
gardless of diurnal period (Table 1). The mean summer water potential of auto-
parasites approached —6.5 MPa, with water potentials averaging 1.2 below par-
asites, which were averaging 1.3 below the hosts (Table 1). However, during the
spring season, water potential ratios were lower between autoparasites and para-
sites (1.0) and between parasites and hosts (0.8) (Table 1).

Significant interactions were detected between diurnal period and seasonality

WATER POTENTIALS OF HOSTS, PARASITES, AND AUTOPARASITES 45

Table 2. Two-way ANOVA of the effects of diurnal period, seasonality, and their interactions on
water potentials of A. greggii hosts, and parasitic and autoparasitic P. californicum plants. Significance
levels; =) P =0:05; **; P= 0.01; ***: P = 0.001: and ns = Non-Significant.

} Host Parasite Autoparasite
Environmental a pS ae ae Rel
variable df F | F P F ee
Diurnal period 3 89.28 0.0000*** 160.05 0.0000*** 260.04 0.0000***
Seasonality l S07 25) 7010000742 1819.61 O.0000*** 2305.72 0.0000***
Diurnal/Seasonality 2) S207 0.000054 21:68" ‘O:0000**=* 19.31 0.0000%*

for water potentials of A. greggii hosts, and parasitic and autoparasitic P. cali-
fornicum plants (P = 0.001; Table 2). Moreover, plant water potentials were sig-
nificantly correlated (P = 0.05) with durnal period and seasonality, and even more
correlated (P = 0.001) with diurnal/seasonality combination (Table 3).

Discussion

Interactive effects of diurnal period and seasonality on water potentials of A.
greggii hosts, and parasitic and autoparasitic P. californicum plants were exam-
ined in the Las Vegas Valley of southern Nevada. Autoparasites consistently and
significantly had lower diurnal and seasonal water potentials than their parasitic
hosts, which in turn had significantly lower water potentials than their A. greggii
hosts.

Diurnal water potentials varied significantly in both spring and summer seasons,
with a greater variation in mid-summer. Plant water potentials declined signifi-
cantly from spring to summer. Seasonal reductions in plant water potentials are
primarily due to reduced water availability in the soil in southern Nevada (Smith
et al. 1995). From casual observations, large portions of parasitic and autoparasitic
P. californicum canopies turned brown as water stress intensified during the peak
of dry summer season. Among the three types of plants, autoparasitic P. califor-
nicum individuals consistently had the lowest water potential because of greatest
water stress. Autoparasites were most water-stressed during midday hours in the
summer. The diurnal/seasonality combination may adversely affect potential car-
bon gain because more and more autoparasitic canopies are turning from green
to dark brown, and thus shorten the potential growth season. Low-host water
potentials may limit the long-term infection and reproductive success of parasites
and autoparasites.

In this study, water potential ratios were similar between autoparasites and
parasites and between parasites and hosts in both spring and summer seasons,

Table 3. Correlation coefficient (R*) for the relationship between diurnal period, seasonality, as
well as diurnal period/seasonality combination and water potentials of A. greggii hosts, and parasitic
and autoparasitic P. californicum plants. Significance levels: *: P = 0.05; **: P = 0.01; ***: P =
0.001; and ns = Non-Significant.

Environmental variable Host Parasite Autoparasite
Diurnal period Oo ea Osos = OL
Seasonality O59 22> OMG) s> OL Peer

Diurnal/seasonality OLSSe= es OL Sys (OASIS) se Sete

46 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

with greater ratios during mid-summer. Parasites obtain limited water and various
mineral nutrients from their hosts; autoparasites in turn obtain even more limited
resources from their parasitic hosts (Lei 2000a). Phoradendron californicum
plants are characterized by very low water use efficiencies, and must maintain
more negative water potentials than their hosts in order to obtain water in southern
California (Jordan et al. 1997). In an autoparasite-parasite system involving P.
californicum with A. greggii as the host, water use efficiency is highest in the
host and lowest in the autoparasite in northwestern Arizona (Ehleringer and
Schulze 1985). The differences in water use efficiency, including transpiration
rates, between host and parasite and between parasite and autoparasite, are of
similar magnitude (Ehleringer and Schulze 1985). Since both parasitic and auto-
parasitic P. californicum plants access the same xylem water from their A. greggii
hosts, autoparasites utilize approximately 10-30% more water per increment
growth than their parasitic host (Ehleringer and Schulze 1985). Both parasites and
autoparasites must constantly acquire water from, and at the expense of, their A.
greggil hosts (Lei 2000a).

Only a limited number of autoparasitic P. californicum plants were observed
under natural field conditions partially because autoparasites, establishing on
heavily infested hosts, experienced a significantly greater water stress than para-
sites. Occasional severe droughts occur in southern Nevada; yet, the timing and
duration of each drought vary considerably. Within a single, heavily infested A.
greggil host, parasites and autoparasites face their own intraspecific interactions,
especially density-dependent interference and exploitation competition. Autopar-
asitism is a condition in which three organisms live together, but autoparasitic P.
californicum plants derive nourishment at the expense of their parasitic hosts,
which in turn derive nourishment from their A. greggii hosts. Under extreme
cases, Acacia greggii hosts can support many adult (well-established) P. califor-
nicum plants before P. californicum plants experience intraspecific competition,
P. californicum-induced, or drought-induced mortality that takes the parasites,
autoparasites, along with their hosts in southern Nevada.

Acknowledgments

I gratefully acknowledge Steven Lei, David Valenzuela, and Shevaun Valen-
zuela for providing valuable field assistance. Steven Lei assisted with statistical
analyses. The Department of Biology at the Community College of Southern
Nevada (CCSN) provided logistical support. The manuscript was greatly im-
proved by comments from David Charlet and an anonymous reviewer.

Literature Cited

Analytical Software 1994. Statistix 4.1, an interactive statistical program for microcomputers. Ana-
lytical Software, St. Paul, Minnesota.

Ehleringer, J. R. and E. D. Schulze. 1985. Mineral concentration in an autoparasitic Phoradendron
californicum growing on a parasitic P. californicum and its host, Cercidium floridum. Amet. J.
Botany 72:568—571.

Hollinger, D. Y. 1983. Photosynthesis and water relations of the mistletoe, Phoradendron villosum,
and its host, the California valley oak, Quercus lobata. Oecologia 60:396—400.

Jordan, L. A., D. N. Jordan, E L. Landau, and S. D. Smith 1997. Parasitism of two codominant desert
plant hosts: lost hostwater potentials may limit long-term infection success. Abstract of the
1997 Ecological Society of America Annual Meeting, Albuquerque, New Mexico.

WATER POTENTIALS OF HOSTS, PARASITES, AND AUTOPARASITES 47

Kaufman, P. B. 1989. Plants: their biology and importance. Harper and Row Publishers, New York.

Kuijt, J. 1969. The biology of flowering parasitic plants. University of California Press, Berkeley,
California, 246 pp.

Lei, S. A. and L. R. Walker 1997a. Classification and ordinatino of Coleogyne communities in southern
Nevada. Great Basin Nat. 57:155—162.

Lei, S. A. and L. R. Walker 1997b. Biotic and abiotic factors influencing the distribution of Coleogyne
communities in southern Nevada. Great Basin Nat 57:163—171.

Lei, S. A. 1999. Age, size and water status of Acacia greggii influencing the infection and reproductive
success of Phoradendron californicum. Amer. Midland Nat. 141:358—365.

Lei, S. A. 2000a. Age and size of Acacia and Cercidum influencing the infection success of parasitic
and autoparasitic Phoradendron. So. Cal. Acad. Sci. 99:45—54.

Lei, S. A. 2000b. Survival and development of Phoradendron californicum and Acacia greggii during
a drought. Western North Amer. Nat. 61:78—84.

Leonard, O. A. and R. J. Hull. 1965. Translocation relationships in and between mistletoes and their
hosts. Hilgardia 37:115—153.

National Oceanic and Atmospheric Administration. 1999. Local climatological data: Annual summary
with comparative data, Las Vegas, Nevada. Published by National Climatic Data Center, Ash-
ville, North Carolina.

Raven, J. A. 1983. Phytophages of xylem and phloem: a comparison of animal and plant sap-feeders.
Advancement Ecol. Res. 13:136—234.

Rowlands, P. G., H. Johnson, E. Ritter, and A. Endo. 1977. The Mojave Desert. Jn: M. Barbour and
J. Major, editors, Terrestrial vegetation of California. John Wiley and Sons, New York.
Scholander, P E, H. T. Hammel, E. D. Bradstreet, and E. A. Hemmingsen. 1965. Sap pressure in

vascular plants. Science 148:339—345.

Smith, S. D., C. A. Herr, K. L. Leary, and J. M. Piorkowski. 1995. Soil-plant water relations in a
Mojave Desert mixed shrub community: a comparison of three geomorphic surfaces. J. Arid
Environments 29:339-351.

Accepted For Publication 28 January 2001.

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CONTENTS

A New Species of the Genus Lile (Clupeiformes: Clupeidae) of the Eastern
Tropical Pacific. José Luis Castro-Aguirre, Gorgonio Ruiz-Campos
and EduardoyE. Talat jo tl 0 ans oh te l

Food habits of the spotted sand bass Paralabrax maculatofasciatus
(Steindachner, 1868) from Laguna Ojo de Liebre, B.C.S., Mexico.
Noemi Bocanegra-Castillo, L. Andrés Abitia-Cardenas, Victor H. Cruz-
Escalona, Felipe Galvan Magania, and Lucia Campos-Davila _. 13

First Specimens of the Fangjaw Eel Echiophis brunneus (Pisces:
Ophichthidae) from the Gulf of California, México. Gorgonio Ruiz-

Campos and José luis Castro-Acuirre 0 eee 24
Observations on nesting seabirds and insular rodents in the Middle Sea of

Cortes in 1999 and 2000. Eric Mellink, Adriana Orozco-Meyer,

Beatriz Contreras, and Monica Gonzalez-Jaramillo _.. ee 28
Macroparasites of Pacific sanddab Citharichthys sordidus (Bothidae) from

polluted waters of the Palos Verdes Shelf, southern California. Cheryl

C, Hosue and)! Jeanie VM Parts 200 Ui ee 36
Interactive Effects of Diurnal Period and Seasonality on Water Potentials of

Acacia, and Parasitic and Autoparasitic Phoradendron. SimonA.Lei_. 42

COVER: Holotype of Lile negrofasciata (CI:2032), adult female, from Bahia de Guasimas, Sonora,
Mexico. Photograph by Gorgonio Ruiz-Campos.

a i:

r ISSN 0038-3872
,Sba

SewtHeERN CALIFORNIA, ACADEMY, OF, SCIENCES

BOULLETIN

Volume 101 Number 2

Qe S slough anchovy
vm q o = Se z
a : bonefish

northern ancho —
Pacific sardine a of =|==<¢ Arm or a
deepbody Qe dwarf
7
» a anchovy & surfperch

California grunion jacksmelt

kelp bass cheekspot goby

“arrow goby

er,

shadow goby
spotted .
kelpfish

YOY turbot

tea £ *& San Diego Bay

~~ es

SPECIES
COMPOSITION

barred sand bass

round stingray California tonguefish

CALIFORNIA |
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© Southern California Academy of Sciences, 2002

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Bull. Southern California Acad. Sci.
101(2), 2002, pp. 49-85
© Southern California Academy of Sciences, 2002

Structure and Standing Stock of the Fish Assemblages
of San Diego Bay, California from 1994 to 1999

Larry G. Allen,” Amy M. Findlay, and Carol M. Phalen

Department of Biology, California State University, Northridge,
Northridge, California 91330-8303.

Abstract.—Twenty quarterly samples were taken of the fish assemblages of San
Diego Bay from July 1994 to April 1999. Each quarter, four stations were oc-
cupied using a variety of sampling methods (large seine, small seines, square
enclosure, purse seine, beam trawl, and otter trawl) designed to assess all com-
ponents of the ichthyofauna. These samples yielded a total of 497,344 fishes
belonging to 78 species and weighing 2,775 kg over the five-year period. Northern
anchovy was the most abundant fish species comprising 43% of the total catch
despite its virtual absence in 1997—98, followed by topsmelt, the slough anchovy
and Pacific sardine. Round stingrays dominated in weight constituting almost 25%
of the total biomass taken followed by spotted sand bass, and northern anchovy.
Both numerical abundance and biomass were highest in the spring and summer
months due largely to heavy recruitment of juvenile surfperches, topsmelt and
northern anchovies. Large catches of northern anchovies, Pacific sardines, round
stingrays, and spotted sand bass also contributed to the pronounced peaks in most
July samples. Approximately 70% of all individual fish captured in San Diego
Bay during this study were juveniles. The 40 most common species/recruits clus-
tered into eleven, resident and seasonal groups. According to canonical correlation
analysis, distance from the mouth of the bay, depth, temperature, and salinity
accounted for nearly 88% (R* = 0.875) of the variance in species abundances.

In general, the fish assemblages of San Diego Bay were found to be diverse,
abundant, highly seasonal, and highly productive. The bay serves as a significant
nursery area for at least 28 species of fish while presenting a unique combination
of harbor, nearshore soft bottom, and bay/estuarine habitats which each contribute
unique sets of species to the overall assemblage. One of these sets includes 12
species which are indigenous to the bays and estuaries of southern California.
South San Diego Bay represents a crtical habitat for these unique bay/estuarine
species whose habitats have disappeared at an alarming rate during the last half
century. The extensive shallow water habitat and eelgrass beds also support a
very high standing stock of midwater, schooling (forage) fishes, such as northern
anchovies, slough anchovies and topsmelt which, in turn, serve as an important
forage resource for larger predatory fishes and marine birds. In addition, the gen-
eral warm and hypersaline waters of south San Diego Bay offer a warm water
refuge for a number of southern, “‘Panamic”’ province fish species making it
unique among all other southern California embayments.

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* Corresponding author.

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50 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

Introduction

Bays and estuaries normally are considered to be important nursery areas for
coastal marine fishes (Haedrich and Hall, 1976; Cronin and Mansueti, 1971). The
warm spring-Summer water temperatures coupled with high productivity enable
these environments to support large numbers of juvenile fish. Southern California
bays and estuaries are relatively small and scarce when compared to the large,
river-dominated estuaries common in other parts of the world. They do, however,
function as nursery areas in the classical sense for some species. At least one
commercially important species (California halibut, Paralichthys californicus) has
been shown to rely heavily on southern California bays and estuaries as nursery
areas (Allen, 1988). Juveniles of non-commercial fishes can be extremely abun-
dant and usually dominate the fish assemblages of bays and estuaries in the South-
ern California Bight (Allen, 1982). Many of these abundant, non-commercial spe-
cies (e.g. gobies, anchovies, and silversides) are important forage fishes for com-
mercial fish species (Horn, 1980) and sea birds. Another characteristic of the fish
assemblages from southern California bays and estuaries which is often over-
looked is that these habitats support a unique set of species found nowhere else
in the bight (Horn, 1980; Allen, 1985).

The principal, resident species found in the smaller bays and estuaries of the
Bight include topsmelt (Atherinops affinis), California killifish (Fundulus parvi-
pinnis), striped mullet (Mugil cephalus), longjaw mudsucker (Gillichthys mira-
bilis), arrow goby (Clevelandia ios), shadow goby (Quietula ycauda), cheekspot
goby CUlypnus gilberti), yellowfin goby (Acanthogobius flavimanus—introduced),
deepbody anchovy (Anchoa compressa), slough anchovy (Anchoa delicatissima),
shiner surfperch (Cymatogaster aggregata), black surfperch (Embiotoca jacksoni),
diamond turbot (Hypsopsetta guttulata), and juvenile California halibut (Parali-
chthys californicus), spotted sand bass (Paralabrax maculatofasciatus), round
stingray (Urolophus halleri), and yellowfin croaker (Umbrina roncador) (Horn
and Allen, 1981).

California killifish and longjaw mudsuckers are most abundant in the shallow
tidal channels of the marsh islands. Topsmelt, striped mullet, deepbody anchovy,
and slough anchovy inhabitat the water column of both the main channels and
along the shoreline, although topsmelt and mullet feed on the bottom. The five
species of gobies (family Gobiidae) as a group are the most abundant benthic
fishes along the shoreline. The deeper channels are inhabited mainly by residents
and seasonal migrants including shiner surfperch, black surfperch, diamond turbot,
juvenile California halibut, spotted sand bass, juvenile barred sand bass, yellowfin
croaker, and round stingray (Horn and Allen, 1981).

San Diego Bay is the largest naturally occurring marine embayment between
San Francisco and Scammon’s Lagoon in central Baja California containing ap-
proximately 12,000 acres (4,858 ha) of marine habitat (San Diego Unified Port,
1990). As a whole, the bay provides expansive and diverse habitats for fishes
including deep channels, marinas, and extensive shallows largely covered with
eelgrass. Only the lower portion, South San Diego Bay, appears comparable to
other Southern California bays and estuaries in terms of physical and biotic char-
acteristics. The overall goal of this study was to provide the first definitive as-
sessment of the fish populations inhabiting this important coastal habitat.

FISH ASSEMBLAGES OF SAN DIEGO BAY Si

Since 1968, the fish populations of San Diego Bay have been the subject of
numerous monitoring studies with most being concentrated in the to the South
San Diego Bay region (Ford 1968, 1985, & 1986, Ford et al. 1971, Lockheed
1979, San Diego Unified Port District 1980, San Diego Gas & Electric Co. 1980,
Lockheed 1983). Most of these studies were limited in scope and duration. A
comprehensive review of all work and the work in South San Diego Bay, in
particular, is presented in San Diego Unified Port District (1990). No comprehen-
sive studies of the fish populations of the entire bay existed prior to the present
study.

San Diego Unified Port District (1990) also presented the most complete work
on the South San Diego Bay fish populations yet completed. Sampling was con-
ducted on a quarterly basis throughout the south bay in 1988-89. The sampling
included multiple gear protocol (otter trawls, gill nets, beam trawls, and two sizes
of beach seine) to effectively sample the major subhabitats utilized by fishes. This
study concluded that the species composition, relative abundances, and biomass
contributions of the south bay fishes have remained very similar since 1968.
Topsmelt, slough anchovy, arrow goby, barred pipefish, and California killifish
were the most numerically abundant species found in South San Diego Bay while
round stingrays, California halibut, and spotted sand bass dominated in terms of
biomass.

Hoffman (1986) compared abundance and biomass of fish utilizing eelgrass
beds and adjacent non-vegetated areas in three sections of San Diego Bay. Beach
seine hauls were made in the north, central, and south portions of the bay on a
quarterly basis from July 1980 through April 1981. Topsmelt, shiner surfperch,
and three species of gobies (arrow, cheekspot, and shadow) made up 93% of the
individuals taken. Topsmelt, shiner surfperch, spotted sand bass, staghorn sculpin,
round stingray, and California halibut comprised more than 87% of the fish bio-
mass sampled. Hoffman (1986) concluded that nearly twice as many individual
fish and fish species were taken at eelgrass sights than non-vegetated sites when
all samples were considered. Furthermore, the total number of individuals and
total biomass seemed to remain relatively constant from season to season in these
shallow nearshore areas. Hoffman’s (1986) results underscore the importance of
the eelgrass habitat in San Diego in supporting juvenile and adult fish populations.
This study served as a major impetus for the present study, which will eventually
provide a statistically reliable comparison of fish numbers and biomass between
vegetated (eelgrass) and non-vegetated areas.

The most recent work on the fishes of San Diego Bay was a long-term beach
seine study also conducted by Hoffman (1995; and unpubl. data). A single station
at the base of the Coronado Bridge has been sampled quarterly since January
1988. This sight corresponds directly with the station 2, vegetated site in the
present investigation.

Finally, since 1985, nine, southern or “‘Panamic’’, fish species have been re-
corded from San Diego that add to the overall species list recorded from the bay
@iable 1).

The overall objectives of this study were to: |) identify, quantify and determine
the seasonal utilization of the fish populations in San Diego Bay, 2) identify key
habitats that support juvenile fish species, and 3) determine geographic and/or
habitat areas of San Diego Bay that support significant populations of fish species

52 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

Table 1. Exotic, southern species recorded in San Diego Bay in the literature from 1985 to 1991.

Common name Scientific name Citation Collection date
Anchoveta Ctengraulis mysticetus Duffy (1987) 1986?
Pacific cervalle jack Caranx caninus Duffy (1987) 1986?
Bonefish Albula vulpes Duffy (1987) 1986?
White mullet Mugil curema Lea et al. (1988) May 1985
Milkfish Chanos chanos Duffy and Bernard (1985) 1985?
Pacific seahorse Hippocampus ingens Jones et al. (1988) a
Cortez grunt Haemulon flaviguttatus Lea and Rosenblatt (1992) May 1991
Bigeye trevally Caranx sexfasciatus Lea and Walker (1995) Nov 1990
Mexican lookdown Selene brevoorti Lea and Walker (1995) Nov 1990

utilized as forage by endangered avian species. To these ends, the following were
determined and will be described for the five-year period, July 1994 to April 1999
in San Diego Bay: 1) physical and chemical (PC) factors, 2) species composition
and abundance, 3) principal species, 4) species diversity, 5) abundance by bay
ecoregion, 6) seasonal abundance, 7) ecological importance of species, 8) nursery
area function, 9) fish assemblage structure, 10) abundance patterns in relationship
to PC factors, 12) numerical and biomass density, 13) density and standing stock
of forage species, and 14) density and standing stock of fisheries species.

Methods and Materials
Station Locations

In order to assess the status of all components of the ichthyofauna of San Diego
Bay, we sampled intensively at four stations located in each of four geographic
sections (north, north-central, south-central, and south) of bay (Figure 1).

At each station, five subhabitat types were sampled. These subhabitats are des-
ignated as follows (from deep to shallow water): 1) channel, 2) nearshore, non-
vegetated, 3) nearshore, vegetated, 4) intertidal, non-vegetated, and 5) intertidal
vegetated.

Sampling Procedures

The actual sampling locations for each type of gear within each station sub-
habitat were selected randomly for each sampling period. Sampling was conducted
on a quarterly basis from July 1994 to April 1999. Each station was occupied on
a separate day in order to sample each section thoroughly with a multiple gear
approach. The use of multiple gears was necessary to adequately sample all of
the habitat types available to the fishes of San Diego Bay. Collections were carried
out using the R/V Yellowfin (California State University) as our base of operations
with much of the work was conducted out of two, 5 m Boston Whalers. At each
station, the following gear types were employed:

1) A 15.2 X 1.8 m large seine fitted with a 1.8 < 1.8 X 1.8 m bag (1.2 cm
mesh in wings and 0.6 cm mesh in bag) was utilized to sample juvenile fishes in
the nearshore portion of the station at a depth of 0—2 m. This net was set parallel
to shore and hauled to shore by 15 m lines. This seine is an accurate sampler of
nearshore schooling fishes and gives reliable density estimates. Two replicate
hauls were made at each station, each of which covered about 220 m7”.

FISH ASSEMBLAGES OF SAN DIEGO BAY Se)

Fig. |. Map of San Diego Bay illustrating the locations of the 4 sampling stations. (N = Non-
vegetated site; V = Vegetated site; C = Channel site).

2) A 4.6 m X 1.2 m small seine (3 mm mesh) was employed to collect juvenile
and adult fishes occupying the shallow, inshore areas (O—O.5 m depth). The small
seine was hauled 10 m along shore and pivoted shoreward yielding a consistent
areal coverage of about 62 m7’.

3) A square enclosure (1m < Im X Im) constructed of 2.5 cm PVC pipe and
canvas was used to sample small, burrow inhabiting fish species such as gobies
in the shallow waters of the bay. The enclosure was set randomly within each
subhabitat in a depth range of 0.25 to 0.75 m and firmly settled into the substrate.
One liter of 3:1 acetone-rotenone solution was then added to the enclosed water
column and the substrate searched thoroughly for 10 min. with a 1 mm mesh,
long-handled dipnet. This device samples an area of 1.0 m’.

4) A 1.6 m beam trawl with 4 mm mesh in the wings and 2 mm knotless mesh
in the codend. Standardized ten minute tows were be made behind the 5m Boston
Whalers covering about 290 m7’.

5) A 66 X 6 m purse seine (1.2 cm mesh in wings and 0.6 cm mesh in bag)
was utilized to sample juvenile and adult fishes in the water column of nearshore
portion and channel of the station. Purse seine hauls were conducted using a
specially out-fitted 5 m Boston Whaler and each sampled about 296 m/°.

6) An 8 m semi-balloon otter trawl (2 cm mesh in wings and 0.8 cm mesh in
codend) towed behind the R/V Yellowfin was used to sample demersal juvenile
and adult fishes from the deepest channel portions of each sampling area covering
an average of 2417 m7’.

54 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

Large seines, small seines, and square enclosures (all N = 3 each) were used
to sample both types of intertidal subhabitat. Both the nearshore subhabitats (non-
vegetated and vegetated) were sampled using beam trawls (N = 3 each) and purse
seines (N = 3 each). The channel was sampled using otter trawls (N = 3) and
purse seines (N = 3).

All fishes or subsamples of large catches were identified, counted and weighed
aboard ship or in the laboratory after freezing, to the nearest 0.1g on a Mettler
PE2000 digital scale.

Water temperature (°C), salinity (ppt), dissolved oxygen (mgO7/1), and pH were
measured at each station at the shoreline, nearshore surface and bottom, and chan-
nel surface and bottom using a Hydrolab Digital 4041 field analyzer. Maximum
depth of,each station was recorded using Lowrance depth sounders mounted on
each Boston Whaler. PC measurements were taken once at each of the four sta-
tions during each of the 4 sampling periods. Unfortunately, technical difficulties
with the D.O. and pH electrodes in October 1996 prevented the measurements of
these parameters during that sampling period.

Data summarization and graphing were accomplished using Microsoft Excel
and Statistica software on an IBM compatible Pentium PC. Data analysis includ-
ing ANOVA, canonical and regular correlations among PC factors and numbers
and biomass were carried out using Statistica. As is the usual case with ecological
data on fishes, raw catch data were generally non-normal with unequal variances.
For this reason, all catch data for number of individuals of all species were log-
transformed (log,)(x + 1)) before statistical comparisons were made. This trans-
formation generally solved problems of normality and unequal variances in this
data set.

The Shannon-Weiner Diversity index (H’):

H’ = -S p,dn p,) where’ p; = proportion of species i

was calculated for total catches by station and total catch by sampling month.
This index incorporates both components of species diversity, species richness
and evenness.

In order to determine the relative importance of each species to the energy flow
within the fish component of the bay ecosystem, an Index of Community Impor-
tance (I.C.I.) was calculated using the total catch for each species over the four
years of the study. This index incorporates the three significant ecological vari-
ables (% Number, % Weight, and % Frequency of Occurrence by station over
month) for each species as follows:

ECT, = (oN, -.% Wi) XX For

The structure of the fish assemblages was examined using cluster analysis (Sta-
tistica). Clustering was based on the log-transformed (log,)(x + 1)), co-occur-
rences of the 35 most abundant species in samples summed over gear-type from
each station over sampling month and utilized complete linkage and the correla-
tion coefficient, 7, as the index for distance.

For the current study, the Best Estimate of Density within each ecoregion was
determined in the following manner: |) Sample densities estimated by gear type
for each species were averaged over all samples within the three depth strata
(Intertidal, Nearshore, and Channel). 2) The maximum density for each species

FISH ASSEMBLAGES OF SAN DIEGO BAY 55

Table 2. Estimates of areal coverage of depth strata within the four Ecoregions of San Diego Bay.
Proportions and areas were used to weight density estimates and to estimate standing stocks of fishes.

Intertidal Nearshore Channel Total % of bay

% AREA Ecoregion
North 6 33 60
North-central 5 38 +7
South-central 3 61 36
South 4 84 3

Hectares/Habitat Ecoregion
North 61 327) 593 982 20
North-central 41 307 460 808 Ly
South-central >I 1227) 726 2005 4]
South 4] 890 133 1064 22
# Hectares 194 Di fay 1913 4858
% Bay Area 4 Si 39

by gear type within the each depth stratum was determined to be the Best Estimate
of Density for that species within that depth stratum. 3) The proportional areal
coverage of the three depth strata within the ecoregion was determined using a
grid on a scaled chart of San Diego Bay (Table 2). These areal proportions were
then used to weight the Best Estimates of Density within the depth strata by
species. A weighted average was then taken among these best estimates over the
three depth strata for each species. 4) The sum of the weighted densities of all
species then represented the Best Estimate of Density (numerical and biomass)
for each depth stratum and the Ecoregion (station). 5) Standing stock estimates
were then made by simply multiplying the best estimates by the total area of the
individual ecoregions and San Diego Bay, as a whole.

Results
Physical and Chemical (PC) Factors

Over the five years of the study, temperature varied from a high of 27.3 °C at
Station 4 in July 1997 to a low of 14.9 °C at Station | in January 1995 and 1997
(Figure 2). Predictably, the highest mean temperatures were also encountered in
the summer of all five years (July 1994, 1995, 1996, 1997 and 1998) and the
lowest in the winter (January 1995, 1996, 1997, 1998 and 1999). In January 1998,
the mean temperature for the entire bay, while being low, was almost 1.5 degrees
higher than the four other January sampling periods. Thermal stratification was
evident during all sampling periods with temperatures becoming warmer (2—5 °C)
north to south (Station 4 being the warmest) in the bay except in October 1994
when Station | had the highest mean temperature (Figure 2).

Surface salinity was relatively stable over the first two years of the study period
varying about 6 ppt (39.8 to 33.4 ppt) over the entire year despite heavy rainfall
in January of 1995 which had little impact on surface salinity. After July 1996
salinities increased to a peak in October 1996 followed by a dramatic drop-off in
January 1997. During the fourth year (1997—98) salinities rose into the summer
months then decreased to an overall low of less than 33 ppt in April 1998. Sa-
linities were typically higher than 34 ppt, the average value for sea water. Mean
salinities peaked in October of each year (1994, 1995, 1996 and 1997) when 35—

SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

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Summary of Mean Surface Temperature (°C) and Salinity (%c) measurements by Station

over the Sampling Months,

2,

Fig.

July 1994 to April 1999.

FISH ASSEMBLAGES OF SAN DIEGO BAY Sy/)

37 ppt prevailed at all stations, but where particularly hypersaline in October 1996
at station 4 (39.8 ppt) (Figure 2). Salinities were generally lower than 34 ppt in
January and April 1998. Overall, mean monthly salinities ranged from 31.6 ppt
in April 1998 to 38.6 ppt in October 1996.

Mean surface pH readings were generally varying only from 7.5 in January
1995 to 8.2 in July 1994 while mean surface dissolved oxygen exhibited a range
of 7.2 to 9.2 mgO,/l in July 1995 and April, 1995, respectively. Unfortunately,
problems with the calibration and the operation of the Hydrolab remote sensing
unit have resulted in numerous unreliable readings for pH and dissolved oxygen.
Therefore, it became necessary to exclude pH and D.O. from most analyses.

The eastern Pacific was subjected to a fairly intense El Nino-Southern Oscil-
lation (ENSO) event in 1997—98. This event was clearly reflected in the temper-
ature readings recorded during our sampling in San Diego Bay. Surface water
temperature was significantly higher in July 1997 (two-way ANOVA, F = 8.34;
df = 3, 4; p < 0.01) than in the four other July samples (1994, 1995, 1996, 1998).
In addition, surface water temperature was significantly higher in January 1998
(two-way ANOVA, F = 5.08; df = 3, 4; p < 0.05) than in the other four January
samples: (19952 1996, 1997, and’ 1999).

Surface water temperatures were also elevated at the beginning of the study in
July 1994 which may have represented a lag effect of the 1992—93 El Nino event.

Abundance and Biomass

A total of 497,344 fishes belonging to 78 species and weighing 2,775 kg were
captured in the 20 sampling dates from July 1994 to April 1998 in San Diego
Bay (Table 3 and 4). Northern anchovy remained as the most abundant fish species
comprising 43% of the total catch despite its virtual absence in 1997—98, followed
by topsmelt at 23%, the slough anchovy at 19%, Pacific sardine at 3% and shiner
surfperch at about 2% of the total catch (Table 3). Round stingrays dominated in
weight constituting almost 25% of the total biomass taken followed by spotted
sand bass at about 14%, northern anchovy at 9%, bat ray, 9%, topsmelt, 9%, and
slough anchovy, 7% (Table 4).

The greatest number of individuals was taken at Station | (198,141) followed
closely by Station 2 (188,147), then Station 3 (57,892), and Station 4 (53,164)
(Figure 3). The high count at Station | and 2 compared to the other stations was
primarily due to the large numbers of juvenile northern anchovy, Pacific sardine,
and topsmelt taken at these stations in most years. This northern portion of the
bay may represent a preferred nursery area for northern anchovy, Pacific sardine,
and topsmelt within San Diego Bay.

The distributions of four of the numerically dominant, schooling species, northern
anchovy, topsmelt, slough anchovy, and Pacific sardine showed an interesting pat-
tern. The station abundances of the northern anchovy, topsmelt, and sardine appear
to have a positive relationship with these three species dominating in north San
Diego Bay. This pattern of abundance was the opposite of that found for the slough
anchovy which was prominent in the southern portion of the bay (Figure 4).

The catch in terms of biomass also showed an interesting pattern across stations
for all species (Figure 5). Large catches of round stingray and spotted sand bass
were taken across all stations. Large catches of northern anchovies at Stations |

58 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

Table 3. Total abundance of fish species taken from San Diego Bay over the five years of the
study, July 1994 to April 1999 by station.

STATIONS, 1994-1999

SCIENTIFIC NAME COMMON NAME 1 2 3 4 TOTAL %
Engraulis mordax northern anchovy 121,888 88,925 3,556 1,249 215,618 43.35
Atherinops affinis topsmelt 44,055 51,041 12,791 7,693 115,580 23.24
Anchoa delicatissima slough anchovy 4.315 25526 31,874 35,106 96,821 19.47
Sardinops sagax Pacific sardine 12,964 1,417 398 74 14,853 2.99
Cymatogaster aggregata shiner surfperch 3,191 3,821 3,194 1,051 11,257. 2.26
Atherinopsis californiensis jacksmelt 399 7,290 664 395 8,748 1.76
Leuresthes tenuis California grunion 4,225 767 600 5,592 1.12
Heterostichus rostratus giant kelpfish 1,687 1,989 881 131 4,688 0.94
Urolophus halleri round stingray 715 1,060 720 1,371 3,866 0.78
Syngnathus leptorhynchus bay pipefish 701 1,394 1,040 292 3,427 0.69
Syngnathus auliscus barred pipefish 390 777 598 917 2,682 0.54
Clevelandia ios arrow goby 51 484 82 1,677 2,294 0.46
Paralabrax nebulifer barred sand bass 311 954 342 240 1,847 0.37
Paralabrax maculatofasciatus — spotted sand bass 226 570 334 347 1,477 0.30
Ilypnus gilbert cheekspot goby 580 582 70 190 1,422 0.29
Paralichthys californicus California halibut 316 200 167 250 933 0.19
Quietula ycauda shadow goby 40 193 84 325 642 0.13
Fundulus parvipinnis California killifish 29 10 598 637 0.13
Mugil cephalus striped mullet 8 1 1 510 520 0.10
Hyporhamphus rosae California halfbeak 18 15 203 174 410 0.08
Anchoa compressa deepbody anchovy 1 212 23 130 366 0.07
Paralabrax clathratus kelp bass 268 24 4 2 298 0.06
Embiotoca jacksoni black surfperch 272 8 280 0.06
Hypsoblennius gentilis bay blenny 128 129 9 1 267 0.05
Hypsopsetta guttulata diamond turbot 69 71 43 74 257 0.05
Micrometrus minimus dwarf surfperch 244 3 2 249 0.05
Seriphus politus queenfish 216 12 228 0.05
Xenistius californiensis salema 76 116 24 2 218 0.04
Pleuronichthys ritteri spotted turbot 120 84 5 8 217 = 0.04
Cheilotrema saturnum black croaker 55 39 31 53 178 0.04
Albula vulpes bonefish 10 115 4 46 175 0.04
Scomber japonicus Pacific mackerel 11 97 20 128 0.03
Umbrina roncador yellowfin croaker 42 4 37 27 110 0.02
Gibbonsia elegans spotted kelpfish 56 35 3 4 98 0.02
Symphurus atricauda California tonguefish 87 11 98 0.02
Porichthys myriaster specklefin midshipmar 27 5 10 37 79 0.02
Xystreurys liolepis fantail sole 62 9 1 72 0.01
Synodus lucioceps California lizardfish 56 4 2 7 69 0.01
Myliobatis californica bat ray 27 2 28 57 0.01
Sphyraena argentea California barracuda 14 43 57 0.01
Scorpaena guttata California scorpionfish 37 8 1 1 47 0.01
Post-larval anchovy Post-larval anchovy 45 45 0.01
Strongylura exilis California needlefish 3 23 9 i 42 0.01
Syngnathus califomiensis kelp pipefish 18 8 14 2 42 0.01
Leptocottus armatus staghorn sculpin 9 12 11 4 36 0.01
Acanthogobius flavimanus yellowfin goby 2 7 25 34 0.01
Cynoscion parvipinnis shortfin corvina 6 8 2 14 30 ~3=0.01
Syngnathus exilis barcheek pipefish 2 i 8 8 25 0.01
Halichoeres semicinctus rock wrasse 24 24 0.00
Oxyjulis californica senorita 24 24 ~=0.00
Gillichthys mirabilis longjaw mudsucker 19 19 0.00
Trachurus symmetricus jack mackerel 18 18 0.00
Cosmocampus arctus snubnose pipefish 10 3 1 14 0.00
Genyonemus lineatus white croaker 13 130.00
Hippocampus ingens Pacific seahorse 7 4 2 13 0.00
Mustelus californicus gray smoothhound 1 1 1 9 12 0.00
Post-larval goby Post-larval goby 9 9 0.00
Anisotremus davidsoni sargo 6 1 i 0.00
Atractoscion nobilis white seabass 3 1 3 7 0.00
Rhinobatis productus shovelnose guitarfish 4 2 1 7 0.00
Girella nigricans opaleye 6 6 0.00
Mustelus henlei brown smoothhound 5 1 6 0.00
Paraclinus integripinnis reef finspot 1 3 2 6 0.00
Pleuronichthys coenosus CO turbot 6 6 0.00
Roncador stearnsii spotfin croaker 1 5 6 0.00
Gymnura marmorata California butterfly ray 2 2 4 0.00
Pleuronichthys verticalis hornyhead turbot 4 4 0.00
Citharichthys stigmaeus speckled sanddab 3 3 0.00
Dorosoma petenense threadfin shad 3 3 0.00
Menticirrhus undulatus California corbina 2 1 3 0.00
Porichthys notatus plainfin midshipman 1 2 3 0.00
Phanerodon furcatus white surfperch 2 2 0.00
Zapteryx exasperata banded guitarfish 2 2 0.00
Gibbonsia metzi striped kelpfish 1 0.00
Heterodontus francisi California hornshark 1 0.00
Medialuna californica halfmoon 1 1 0.00
Pseudupeneus grandisquamous_ red goatfish 1 1 0.00
Pleuronectess vetulus English sole 1 1 0.00
Rimicola muscarum kelp clingfish 1 1 0.00
Tridentiger trigonocephalus chameleon goby 1 1 0.00
TOTAL 198,141 188,147 57,892 53,164 497,344

Number of Species = 78

FISH ASSEMBLAGES OF SAN DIEGO BAY 59

Table 4. Total biomass (g) of fish species taken from San Diego Bay over the five years of the
study, July 1994 to April 1999 by station.

STATIONS, 1994-1999

SCIENTIFIC NAME COMMON NAME 1 2 3 4 TOTAL (g) %
Urolophus halleri round stingray 175,747 167,033 123,010 221,280 687,070 24.76
Paralabrax maculatofasciatus spotted sand bass 65,634 152,308 87,005 77,259 382,206 ETA
Engraulis mordax northern anchovy 138,927 115,387 2,486 1,498 258,297 9.31
Myliobatis californica bat ray 175,731 17,500 61,336 254,568 9.17
Atherinops affinis topsmelt 104,236 78,188 29,324 39,800 251,547 9.06
Anchoa delicatissima slough anchovy 10,395 61,171 65,690 45,201 182,456 6.57
Paralabrax nebulifer barred sand bass 27,180 35,350 13,494 46,907 122,931 4.43
Paralichthys californicus California halibut 38,017 22,443 21,142 30,770 112,373 4.05
Cymatogaster aggregata shiner surfperch 26,621 28,134 7,929 3,653 75,933 2.74
Sardinops sagax Pacific sardine 46,650 5,547 7,560 4,711 64,467 2.32
Atherinopsis californiensis jacksmelt 24,109 4,210 2,231 13,875 44,424 1.60
Heterostichus rostratus giant kelpfish 14,273 13,589 8,407 1,034 37,303 1.34
Hypsopsetta guttulata diamond turbot 13,600 12,198 4,681 6,228 36,707 1.32
Leuresthes tenuis California grunion 15,245 10,801 10,007 36,053 1.30
Cheilotrema satumum black croaker 5,533 4,520 4,202 8,500 22,756 0.82
Rhinobatis productus shovelnose guitarfish 10,150 6,595 3,757 20,502 0.74
Scomber japonicus Pacific mackerel 4,128 11,405 3,647 19,180 0.69
Umbrina roncador yellowfin croaker 5,684 499 5,793 4,492 16,469 0.59
Pleuronichthys ritteri spotted turbot 7,829 7,843 154 121 15,948 0.57
Embiotoca jackson! black surfperch 13,858 344 14,202 0.51
Cynoscion parvipinnis shortfin corvina 4,679 4,981 1,476 801 11,937 0.43
Gymnura marmorata California butterfly ray Ten 2,714 10,441 0.38
Xystreurys liolepis fantail sole 4,674 4,175 188 9,036 0.33
Scorpaena guttata California scorpionfish 6,400 1,161 151 182 7,893 0.28
Seriphus politus queenfish 6,222 169 6,392 0.23
Mustelus californicus gray smoothhound 336 968 950 3,793 6,047 0.22
Mustelus henlei brown smoothhound 4,536 813 5,349 0.19
Porichthys myriaster specklefin midshipman 2,040 384 1,394 926 4,744 0.17
Trachurus symmetricus jack mackerel 4,095 4,095 0.15
Strongylura exilis California needlefish 483 1,771 363 1,137 3,753 0.14
Micrometrus minimus dwarf surfperch 2,971 38 28 3,037 0.11
Paralabrax clathratus kelp bass 2,309 496 29 83 2,917 0.11
Xenistius califomiensis salema 44 2,508 260 27 2,840 0.10
Sphyraena argentea California barracuda 2,009 821 2,830 0.10
Menticirrhus undulatus California corbina 2,600 150 2,750 0.10
Anchoa compressa deepbody anchovy 2 592 454 1,479 2,527 0.09
Heterodontus francisi California hornshark 2,420 2,420 0.09
Symphurus atricauda California tonguefish 1,976 379 2,354 0.08
Hypsoblennius gentilis bay blenny 911 1,210 205 3 2,329 0.08
Syngnathus leptorhynchus bay pipefish §12 650 1,042 101 2,304 0.08
Mugil cephalus striped mullet 2 10) 0) 2,270 2,272 0.08
Albula vulpes bonefish 133 744 42 880 1,799 0.06
Girella nigricans opaleye 1,796 1,796 0.06
Atractoscion nobilis white seabass 909 250 568 Wnt27/ 0.06
Synodus lucioceps California lizardfish 1,473 54 45 73 1,645 0.06
Syngnathus auliscus barred pipefish 313 406 378 519 1,615 0.06
Fundulus parvipinnis California killifish 111 25 1,318 1,454 0.05
Roncador stearnsii spotfin croaker 102 1,163 1,265 0.05
Zapteryx exasperata banded guitarfish 1,067 1,067 0.04
Hyporhamphus rosae California halfoeak 51 29 676 303 1,059 0.04
Pleuronichthys coenosus CO turbot 867 867 0.03
Acanthogobius flavimanus yellowfin goby 22 388 420 830 0.03
Halichoeres semicinctus rock wrasse 743 743 0.03
Oxyjulis californica senorita 667 667 0.02
Genyonemus lineatus white croaker 610 610 0.02
Phanerodon furcatus white surfperch 605 605 0.02
Anisotremus davidsoni sargo 18 579 597 0.02
Pleuronichthys verticalis hornyhead turbot 597 597 0.02
Hippocampus ingens Pacific seahorse 267 129 91 487 0.02
Leptocottus armatus staghorn sculpin 119 119 123 60 420 0.02
Gibbonsia elegans spotted kelpfish 165 150 28 9 352 0.01
Quietula ycauda shadow goby 18 30 117 103 268 0.01
Ilypnus gilberti cheekspot goby 115 37 7 71 231 0.01
Clevelandia ios arrow goby 8 26 6 187 227 0.01
Dorosoma petenense threadfin shad 224 224 0.01
Syngnathus californiensis kelp pipefish 86 38 15 3 142 0.01
Pseudupeneus grandisquamous red goatfish 100 100 0.00
Porichthys notatus plainfin midshipman 9 61 69 0.00
Gillichthys mirabilis longjaw mudsucker 51 51 0.00
Citharichthys stigmaeus speckled sanddab 37 37 0.00
Cosmocampus arctus snubnose pipefish 2 29 0 31 0.00
Post-larval goby Post-larval goby 30 30 0.00
Syngnathus exilis barcheek pipefish 5 7 8 7 27 0.00
Pleuronectes vetulus English sole 5 5 0.00
Paraclinus integnpinnis reef finspot 1 1 3 5 0.00
Tridentiger tigonocephalus chameleon goby 4 4 0.00
Post-larval anchovy Post-larval anchovy 1 1 0.00
Gibbonsia metzi striped kelpfish 0 0) 0.00
Medialuna californica halfmoon (0) 0 0.00
Rimicola muscarum kelp clingfish 0 0 0.00
TOTAL 985,530 759,210 440,185 590,386 2,775,311

60 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

Sta 1

120,000

100,000

Sta 2

a3 \A\Y\R\ AB
. Sta 4 BE \-

94-95 95-96 96-97 97-98 98-99
Year

80,000

-60,000

Number

40,000

20,000

0

Fig. 3. Abundance of San Diego Bay Fishes by Station, 1994-1999.

and 2, in addition to those of stingrays and spotted sand bass yielded much higher
biomass catches in the northern part of the bay.

Abundance by Bay Ecoregion

North (Station 1).—A total of 198,141 fishes belonging to 68 species and
weighing 985.5 kg were captured in the North Ecoregion over the 20 sampling

140,000

a Engraulis mordax
@ Atherinops affinis
O Anchoa delicatissima

120,000 4~

G Sardinops sagax

400,000 -}~

80,000

Number

60,000 -|~

40,000 4~

20,000 +

Station

Fig. 4. Abundance of the four numerically dominate species by station in San Diego Bay, July
1994 to April 1999.

FISH ASSEMBLAGES OF SAN DIEGO BAY 61

Biomass (kg)

al % a T

94-95 95-96 96-97

97-98 98-99
Years

Fig. 5. Biomass (kg) of San Diego Bay Fishes by Station, 1994-1999.

dates from July 1994 to April 1999 (Table 3 and 4). Northern anchovy was the
most abundant fish species comprising 62% of the total catch, followed by tops-
melt at 22%, Pacific sardine at 5%, slough anchovy, 2%, California grunion (Leu-
resthes tenuis), 2% and shiner surfperch at about 2% of the total catch. Round
stingrays led in total biomass at 18% followed closely by bat rays also at 18%,
northern anchovy at 14%, topsmelt, 11%, spotted sand bass, 7%, and California
halibut, 4%.

North-Central (Station 2).—A total of 188,147 fishes belonging to 55 species
and weighing 759.2 kg were captured in the North-Central Ecoregion over the 20
sampling dates from July 1994 to April 1999 (Table 3 and 4). Northern anchovy
remained the most abundant fish species comprising nearly 47% of the total catch,
followed by topsmelt at 27%, slough anchovy at 14%, jacksmelt at 4%, shiner
surfperch at about 2%, and giant kelpfish at approximately 1% of the total catch.
Round stingrays constituted the largest portion of total biomass at 22%, followed
closely by spotted sand bass, 20%, northern anchovy, 15%, topsmelt, 10%, and
slough anchovy at almost 8% (Figure 6).

South-Central (Station 3).—A total of 57,892 fishes belonging to 49 species
and weighing 440.2 kg were captured in the South-Central Ecoregion over the 20
sampling dates from July 1994 to April 1999 (Table 3 and 4). Slough anchovy
was the most abundant fish species comprising 55% of the total catch, followed
by topsmelt at 22%, northern anchovy at 6%, shiner surfperch at about 6%, and
bay pipefish at approximately 2% of the total catch. Round stingrays ranked first
in total biomass at 28% followed closely by spotted sand bass at 20%, slough
anchovy, 15%, topsmelt, 7%, and California halibut, 5%.

South (Station 4).—A total of 53,164 fishes belonging to 51 species and weigh-
ing 590.4 kg were captured in the South Ecoregion over the 20 sampling dates
from July 1994 to April 1999 (Table 3 and 4). As with station 3, slough anchovy

62 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

<a i
~ Bene ey

Pacific mackerel 5 salema
A cent

bonefish
Pacific ene a kelp bass cheekspot goby

rf
deepbody Paes ipefis
pe easter oy is

aes grunion jacksmelt
—S ATE
s A é bay p et ;
eee a 2, P je D SS <
a’ oe Aa oced YOY halibut
queenfish black — a kelpfish ES
YOY turbot

see Sal bass ~ for i eg 4 9 9 4 ig [ 9 9 9

es A Co SPECIES
barred sand bass _ . ce < \ Cc O M PO S | Tl O N

round stingray California tonguefish

Fig. 6. Diagrammatic representation of the common and distinctive species of fish which occurred
in the northern portion (North and North Central Ecoregions) of San Diego Bay during the study
period of July 1994 to April 1999.

was, again, the most abundant fish species comprising over 66% of the total catch,
followed by topsmelt at 14%, arrow goby at 3%, round stingray at also at 3%,
and shiner surfperch at 2% of the total catch. Once again, round stingrays led in
total biomass at nearly 37% of the total biomass followed by spotted sand bass
at 13%, bat ray at 10%, and barred sand bass at 8% (Figure 7).

South San Diego Bay provides critical habitat for at least 12 fish species (Table
5) which are indigenous to bay and estuarine environments in the Southern Cal-
ifornia Bight (Allen, 1985).

Seasonal Abundance

Marked changes in the number individuals and total biomass occurred season-
ally over the course of the study. When all four stations are considered together,
numerical abundance was generally highest in the spring (April 1995, 1996, 1997,
1998, and 1999) and summer (July 1995, 1996, and 1998) months (Figure 8).
Heavy recruitment of juvenile surfperches and topsmelt in April of 1995 and 1996
was largely responsible for those abundance peaks (Table 6). Large numbers of
topsmelt, slough anchovy, shiner surfperch and California grunion were respon-
sible for relatively high catches in April 1997, while the April 1998 catches were
dominated by slough anchovies. Very large catches of juvenile northern anchovy
and Pacific sardine caused the pronounced peaks in July 1995 and 1996. Inter-
estingly, July 1997 catches were low due to the virtual absence of northern an-
chovies. The catch in July 1998 was dominated by slough anchovy, northern

FISH ASSEMBLAGES OF SAN DIEGO BAY 63

re mx 8) = — § ——
California halfbeak i <g ~ Z x SEE mK

bonefish

Sy
slough anchovy

topsmelt

<< aa aE , Rea shiner curfpench California killifish
- wo is => . Gti Relogs
Cains

barredjpipefish

ra ee

bay pipefish
striped mullet

shortfin corvina
black croaker arrow goby

SOUTH
San Diego Bay
1994 - 1999

at i : = - SPECIES
barred sand bass ‘$ < COMPOSITION

diamond turbot

Fig. 7. Diagrammatic representation of the common and distinctive species of fish which occurred
in the southern portion (South Central and South Ecoregions) of San Diego Bay during the study
period of July 1994 to April 1999.

anchovy, and topsmelt. Lowest abundances were generally encountered in the
coldest months of the study (January 1995, 1996, 1997, and 1999) with the Jan-
uary 1998 sample containing about 3X the number of fishes as the previous
January samples due to a large recruitment of jacksmelt. This abundance pattern
was consistent among Stations 1, 2, and 3. However, the southern-most station,
4, exhibited peak abundance in October 1994, October 1996, and April 1998
(Figure 8).

Biomass varied greatly from quarter to quarter and was largely related to the
abundance of northern anchovy, round stingrays, bat rays, and spotted sand bass
in the catch (Table 7). In the first four years of the study, weights of the catches
consistently peaked in the spring (April 1995, 1996, 1997 and 1998) and the
summer (July 1995 and 1996) except for July 1997(Figure 9). Significant catches
of bat rays in October 1998 (Station 1) and January 1999 (Station 4) greatly
disrupted this earlier pattern (Figure 9).

The general seasonal patterns of abundance and distribution of fishes in the north-
ern and southern portions of San Diego Bay are depicted in Figures 10 and 11.

Nursery Area Function

Approximately 70% of all individual fish captured in San Diego Bay during
this study were juveniles. In fact, 28 of the 35 most abundant species were rep-
resented by over 50% juveniles (Table 8). Of these, ten species were represented
by more than 90% juveniles including the most abundant species, northern an-

SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

64

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FISH ASSEMBLAGES OF SAN DIEGO BAY 65

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Fig. 8. Abundance of San Diego Bay Fishes by Station over Sampling Months, 1994—1999.

chovy (100% juveniles). This high proportion of juveniles overall in the catch
underscores the importance of the San Diego Bay system as an important nursery
area for a large number of fish species.

Species Importance

The Index of Community Importance (Table 9) incorporates three significant
ecological variables (% Number, % Weight, and %Frequency) for each species and
yields a value that is indicative of the importance of each species to the energy
flow within the fish component of the bay ecosystem. When all three factors are
taken into account, topsmelt rank first among all San Diego Bay fish species with
an I.C.I. of 3230. Round stingrays ranked second with an I.C.I. of 2553 followed
by northern anchovy with 2271(only 45% frequency within stations by sampling
month), slough anchovy with 1790, and spotted sand bass with 1354.

Species Diversity

Species richness (number of species) was generally highest in the northern
section of the bay nearest the bay mouth (Station 1—2) being highest at station |
(Figure 12). H’ diversity which incorporates evenness of relative species abun-
dances was found to be highest in the southern portion of the bay (Station 3—4)
peaking at about H’ = 1.5. The higher H’ values in the south bay reflect the
lower numerical dominance by one or two species at these stations. Northern
anchovy was the numerically dominant species overall at Station | in the North
Bay while slough anchovy dominated Station 4 in the South Bay.

In the first three years of this study (July 1994 to April 1997), species richness
consistently peaked between 40 and 50 species in the spring-summer months
(April and July) (Figure 12). This pattern was disrupted in April and July 1997

SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

66

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67

FISH ASSEMBLAGES OF SAN DIEGO BAY

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68 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

Biomass (kg)

yi \
SEN

w+
St
|
a)

Nov-94
Mar-95
Jul-95
Nov-95
Mar-96
Mar-97
Jul-97
Nov-97
Mar-98
Jul-98
Nov-98
Mar-99

Jul-96
Nov-96

Sampling Month

Fig. 9. Biomass (kg) of San Diego Bay Fishes by Station over Sampling Months, 1994-1999.

when only 37 and 35 total species were captured. Within the last two sampling
years the April and July catches included only 24 to 37 species. In 1997-1999,
the highest number of species was actually taken in October 1997. H’ diversity
followed a pattern which was typically the inverse of species richness in the first
three years. H’ was typically highest in October and January reflecting the higher
evenness of species abundances during these months. The generally lower H’
values in April and July were due to the numerical dominance a few species in
these months. Again, this pattern changed starting in 1997 when April and, es-
pecially July had relatively high H’ values. The relatively low recruitment of
shiner surfperch in April 1997 and the lack of the usual occurrence of large
numbers of northern anchovies in July 1997 were primarily responsible for this
change. H’ values rose again in July and October 1998 indicating a partial return
to the pattern observed in the first three years of the study.

Fish Assemblage Structure

Fish assemblage structure was examined using cluster analysis. The clustering
strategy was based on co-occurrences of the species ranking in the top 35 in
numerical abundance or in the top 20 in biomass and yielded 11 distinct species
and eight site groupings (Figure 13). The species groups reflected the varying
abundances and distributions of these species in space and time (Figure 14). Spe-

FISH ASSEMBLAGES OF SAN DIEGO BAY 69

NORTH BAY
JANUARY

Fig. 10. Diagrammatic representation of the general, seasonal occurrence of the common species
of fish occuring in the northern portion (North and North Central) of San Diego Bay during the study
period of July 1994 to April 1999.

cies groups which occurred in both the intertidal and nearshore depth strata are
characterized as “‘inshore”’ below.

Species Group I.—This group contained three species of inshore, wide-spread,
resident and summer-seasonal, schooling (midwater) fishes. Topsmelt, California
grunion, Pacific sardine, were numerically dominant species, particularly, in the
north-central bay during the spring-summer months when large numbers of their
young-of-the-year (YOY) occurred. Topsmelt represented the truly resident mem-
ber of this group which was abundant at all stations in the bay with YOY oc-
curring in highest abundance in spring samples (April). All members of this group
also occurred in lower abundance in the midwater regions of the channels.

Species Group II.—This group of three, inshore, summer-seasonal, eelgrass-
associated fishes occurred only in the north and north-central portion of the bay.
These included the surfperch species, the black surfperch (Embiotoca jacksont),
dwarf surfperch (Micrometrus minimus), and spotted kelpfish (Gibbonsia ele-
gans). Most of the individuals of these species were YOY.

Species Group III.—This small group included two, inshore, north bay, resi-
dent, spring-recruiting fishes. YOY of the flatfish, California halibut (Paralichthys
californicus) inhabited the intertidal areas along with all age groups of the cheek-
spot goby (lypnus gilberti).

Species Group IV.—This group of inshore, resident & summer-seasonal, eel-
grass-associated fishes included the YOY of kelp bass (Paralabrax clathratus),

70 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

Fig. 11. Diagrammatic representation of the general, seasonal occurrence of the common species
of fish occuring in the southern portion (South Central and South Ecoregions) of San Diego Bay
during the study period of July 1994 to April 1999.

salema (Xenistius californiensis), spotted sand bass (Paralabrax maculatofascia-
tus), and bay blenny (Hypsoblennius gentilis). All of these species used the eel-
grass beds of the north bay as nursery areas.

Species Group V.—This group included four, inshore, resident, eelgrass-asso-
ciated fishes which occurred throughout the bay with the greatest abundance in
the north, north-central, and south-central portions. Species included the shiner
surfperch (Cymatogaster aggregata) and the cryptically-colored fishes, the giant
kelpfish (Heterostichus rostratus), barred pipefish (Syngnathus auliscus), and bay
pipefish (Syngnathus leptorhynchus).

Species Group VI.—This is a group of five, inshore, primarily south bay, res-
ident schooling and benthic species. The numerically dominant, resident fish in
the south-central and south bay, the slough anchovy (Anchoa delicatissima), clus-
tered in this group along and California halfbeak (Hyporhamphus rosae), the
deepbody anchovy (Anchoa compressa), the California killifish (Fundulus par-
vipinnis) and arrow goby (Clevelandia ios).

Species Group VII.—This group included five taxa of inshore, south bay, resi-
dent, species which recruited in the winter months and remained abundant into the
spring of some years. Included in this group were bonefish (Albula vulpes) along
with striped mullet (Mugil cephalus), jacksmelt (Atherinopsis californiensis), shad-
ow goby (Quietula ycauda), and YOY of diamond turbot (Hypsopsetta guttulata).

Species Group VIII.—A group of three, nearshore and channel, summer-sea-

FISH ASSEMBLAGES OF SAN DIEGO BAY GA

Table 8. Estimated percent of juveniles in the catch of the top 35 species of fish from San Diego
Bay, July 1994—April 1999.

Scientific name Common name Jo juv
Engraulis mordax northern anchovy 100
Gibbonsia elegans spotted kelpfish 100
Heterostichus rostratus giant kelpfish 100
Paralabrax clathratus kelp bass 100
Paralichthys californicus California halibut 99
Albula vulpes bonefish 99
Paralabrax nebulifer barred sand bass 97
Sardinops sagax Pacific sardine 96
Mugil cephalus striped mullet 95
Xenistius californiensis salema 94
Clevelandia ios arrow goby 79
Syngnathus auliscus barred pipefish 78
Syngnathus leptorhynchus bay pipefish 76
Atherinops affinis topsmelt 73
Seriphus politus queenfish a3
Fundulus parvipinnis California killifish Toe
Quietula ycauda shadow goby vA
Atherinopsis californiensis jacksmelt 69
Porichthys myriaster specklefin midshipman 67
Ilypnus gilberti cheekspot goby 67
Embiotoca jacksoni black surfperch 66
Leuresthes tenuis California grunion 66
Umbrina roncador yellowfin croaker 66
Micrometrus minimus dwarf surfperch 63
Xystreurys liolepis fantail sole 61
Urolophus halleri round stingray 3)8)
Cymatogaster aggregata shiner surfperch ail
Anchoa delicatissima slough anchovy 43
Hypsoblennius gentilis bay blenny 37
Cheilotrema saturnum black croaker 36
Pleuronichthys ritteri spotted turbot 35
Anchoa compressa deepbody anchovy 23
Paralabrax maculatofasciatus spotted sand bass pip
Hypsopsetta guttulata diamond turbot 18

Average % juveniles 69

sonal, schooling fishes, which primarily occurred in the north bay. The most
abundant, seasonal species in the study, the northern anchovy (Engraulis mordax),
clustered in this group along with the highly summer-seasonal species, Pacific
mackerel (Scomber japonicus) and queenfish (Seriphus politus).

Species Group [X.—Clustering designated this group of large, predatory, ben-
thic species which were resident in the nearshore areas and channels of all sections
of the bay. This group was represented by the larger size classes of the the spotted
sand bass (Paralabrax maculatofasciatus) and barred sand bass (Paralabrax ne-
bulifer), and all size classes of round stingray (Urolophus halleri) and black croak-
er (Cheilotrema saturnum).

Species Group X.—This group was made up of three large carnivores which
occupied the nearshore and channel areas in low to moderate numbers throughout
the bay, but were most often captured in the south bay. The group included

q2, SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

Table 9. Percent number (%N), percent biomass (%WT), percent frequency of occurrence
(% FREQ), and Index of Community Importance (I.C.I.) for the top 50 species (ranked by I.C.I.) of
fishes from San Diego Bay, July 1994—April 1999.

RANK Common Name %N YWWT %FREQ 1.C.1.
1 topsmelt 23.24 9.06 100.00 3230.3
2 round stingray 0.78 24.76 100.00 2553.4
3 northern anchovy 43.35 9.31 45.00 2369.7
4 slough anchovy 19.47 6.57 68.75 1790.4
5 spotted sand bass 0.30 Ue s7/7 96.25 1354.1
6 barred sand bass 0.37 4.43 96.25 462.1
if California halibut 0.19 4.05 100.00 423.7
8 shiner surfperch 2.26 2.74 12250 362.5
g Pacific sardine 2.99 2:32 40.00 212.4
10 giant kelpfish 0.94 1.34 75.00 171.5
11 bat ray 0.01 9.17 375 126.3
12 jacksmelt 1.76 1.60 36.25 121.8
13 diamond turbot 0.05 Wc 86.25 118.5
14 bay pipefish 0.69 0.08 91.25 70.5
15 barred pipefish 0.54 0.06 85.00 50.8
16 California grunion tal2 1.30 20.00 48.5
Wi. black croaker 0.04 0.82 52.50 44.9
18 spotted turbot 0.04 0.57 55.00 34.0
19 arrow goby 0.46 0.01 67.50 Sile7

20 yellowfin croaker 0.02 0.59 Sik25 19.2
21 cheekspot goby 0.29 0.01 61.25 18.0
22 black surfperch 0.06 0.51 ens 2-1
23 fantail sole 0.01 0.33 27.50 9.4
24 Pacific mackerel 0.03 0.69 11.25 8.1

25 shadow goby Orl3 0.01 53.75 1.5
26 California scorpionfish 0.01 0.28 22.50 6.6
27 specklefin midshipman 0.02 (O)EAN ZA 35.00 6.5
28 California halfbeak 0.08 0.04 53.75 6:5
29 California killifish ONS 0.05 33:75 6.1

30 bay blenny 0.05 0.08 43.75 6.0
31 shortfin corvina 0.01 0.43 Wee) 6.0
32 kelp bass 0.06 0.11 36.25 6.0
33 California needlefish 0.01 0.14 28:75 4.1

34 deepbody anchovy 0.07 0.09 23.75 3.9
35 shovelnose guitarfish 0.00 0.74 5.00 3.7
36 California tonguefish 0.02 0.08 28.75 3.0
37 queenfish 0.05 0.23 10.00 2.8
38 gray smoothhound 0.00 0.22 12.50 2.8
39 striped mullet 0.10 0.08 13:75 2.6
40 salema 0.04 0.10 17.50 2.6
41 dwarf surfperch 0.05 0.11 15.00 2.4
42 California butterfly ray 0.00 0.38 5.00 Lig,
43 California lizardfish 0.01 0.06 21.25 1.6
44 bonefish 0.04 0.06 15.00 1:5
45 California barracuda 0.01 0.10 §.75 1.0
46 yellowfin goby 0.01 0.03 20.00 0.7
47 spotted kelpfish 0.02 0.01 17.50 0.6
48 Pacific seahorse 0.00 0.02 27.50 0.6
49 brown smoothhound 0.00 0.19 2;50 0.5

50 staghorn sculpin 0.01 0.02 20.00 0.4

FISH ASSEMBLAGES OF SAN DIEGO BAY 13

H' Diversity H' Diversity
= a 2 OFT aa = a =

Station Month

Species Richness

Tapas wae aT

Number of Species
Number of Species

|
|
}
|
}
i
/
|
j
i
]

Station

Fig. 12. Number of species (species richness) and Shannon-Weiner Diversity (H’) of fishes in San
Diego Bay by station and sampling month, July 1994—April 1999.

resident (Shortfin corvina, Cynoscion parvipinnis and bat rays, Myliobatis cali-
fornicus) and summer seasonal (yellowfin croaker, Umbrina roncador) species.

Species Group XI.—This group included four species of resident, benthic, flat-
fish species which occurred throughout the bay primarily in the channels. Included
in this group were the larger juveniles and adults of California halibut (Paralich-
thys californicus) and diamond turbot (Hypsopsetta guttulata) which were dis-
tributed in all depth strata. The remaining two species (spotted turbot (Pleuronich-
thys ritteri) and California tonguefish (Symphurus atricauda)) mainly occupied
the channels of the north bay.

Relationship of PC factors to Fish Distribution and Abundance

Canonical correlation was utilized to estimate the relationship of the four prom-
inent PC factors of station (as a surrogate for distance from the mouth of the
bay), depth, temperature, and salinity to the individual station abundances (log, (x
+ 1)) of the 35 most abundant species. These four PC factors accounted for nearly
88% (R* = 0.875) of the variance in individual species abundance among stations
over sampling month (Table 10). This extremely high R? value served to under-
score the great influence which relatively few environmental factors can have on
the distribution and abundance of fishes over time.

As a result of this highly significant relationship, the eleven species groups
determined through cluster analysis discriminated very well among the first three,
significant discriminate roots (Figure 15).

74 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

Linkage Distance
SPECIES
16 4°42" 1.0 08 06 64 .O2 700 GROUP

Atherinops affinis
Sardinops sagax 1
Leuresthes tenuis

Gibbonsia elegans

Micrometrus minmus 2
Embiotoca jacksoni
Paralichthys californicus r 3

Ilypnus gilberti

Xenistius californiensis
Paralabrax maculatofasciatus r
Paralabrax clathratus r
Hypsoblennius gilberti
“Syngnathus leptorhynchus
Syngnathus auliscus 5
Heterostichus rostratus
Cymatogaster aggregata
“Anchoadelicatissima—~—S
Anchoa compressa
Hyporhamphus rosae 6
Fundulus parvipinnis
Clevelandia ios

Quietula ycauda

Mugil cephalus

Atherinopsis californiensis 7
Hypsopsetta guttulata r

Albula vulpes

Scomber japonicus
Seriphus politus 8
Engraulis mordax

Urolophus halleri

Paralabrax maculatofasciatus 9

Paralabrax nebulifer

Cheilotrema saturnum
“Umbrinaroncador tS

Myliobatis californicus 1 0
_Cynoscion parvipinnis, _ ____

Symphurus atricauda

Pleuronichthys ritteri 4 4

Paralichthys californicus

| | i lf

lil

Hypsopsetta guttulata

Fig. 13. Results of the cluster analysis of the top 40 fish species or recruits based on co-occurrences
in station/ depth strata samplescollected from July 1994 to April 1999 in San Diego Bay (r = new
recruits of the species).

Standing Stock Estimates

All Fish Species.—Over the entire bay for all five years, the total best estimate
of numerical density was 1.75 indiv./m? (Table 11). Based on a surface area of
approximately 4858 ha, San Diego Bay, on average, contained almost 85 million
fish during this time. Most of the individuals are made up of northern anchovies
(42 million), but there were also, again on average, almost 18 million slough
anchovies, 10 million topsmelt, 3 million sardines, 3 million arrow gobies, and
nearly 2 million shiner surfperch. Among the most common, higher-level carni-
vores, there are about 280,000 round stingrays, 169,000 spotted sand _ bass,
133,000, barred sand bass, and almost 80,000 California halibut.

The total best estimate of biomass density was 7.05 g/m? (Table 12). Again,
based on area, during 1994-1999, San Diego Bay, on average, contained about
340 metric tons (mt) of fish. On a yearly basis most of the biomass was made up
of northern anchovies (52 mt), spotted sand bass (50 mt), round stingrays (49
mt), topsmelt (37 mt), and slough anchovy (36 mt).

The best estimate process yielded an overall biomass density (7.05 g/m?) which

FISH ASSEMBLAGES OF SAN DIEGO BAY 75

Site Groups

a ff oo

fer)

Species Groups

Site Group
Description

Intertidal
North to South Central {=
January - Apnil

Nearshore
All Bay
January

Inshore
South Bay
July - October

Intertidal
Station 4 only
All Months

Inshore
Station 1
April & October

Nearshore
North to South Central
April - October

Channel
North to South Central
All Months

Channel
All Bay
April - October

Fig. 14. Two-way table depicting the relative abundances of species within site groups derived by
cluster analysis. Circles represent abundances of the individuals within the species of a species group
at each of the eight site groups. Site groups are described according to there distribution in space over

time.

Table 10. Results of canonical correlation analysis for four PC factors (Station, Depth, Temperature,
Salinity) versus log-abundance of the 35 most abundant individual species taken in each quarterly
sampling from San Diego Bay, July 1994—April 1999.

Root
removed

0

1
2
3

STA
DEPTH
TEMP
SAL

Chi-square tests with successive roots removed

Canonical Canonical
R R-sar. Chi-sar. df p
0.935 0.875 923.474 160 <0.0001
0.835 0.698 473.408 ial <0.0001
0.642 0.412 214.440 76 <0.0001
0.607 0.368 99.480 39 <0.0001

Canonical weights, physical-chemical factors

Root 1 Root 2 Root 3
0.106 0.952 —0.037
—0.992 0.184 0.071
—0.032 0.097 0.664
0.053 0.040 = |! (0535

76 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

Species
Group

(Hidaq) | LOOY

NOOR WM =

a >}

Fig. 15. Three-dimensional plot of species within species groups by three significant discriminant
roots.

was over three times higher than that (2.03 g/m? ) derived from taking the simple
mean of individual gear densities. This discrepancy is due to the artificial bias
introduced when catches from gears with dramatically different efficiencies are
simply averaged quantitatively with no regard to quality of the estimate.

Forage Species.—Forage species are defined herein as those which are acces-
sible to diving avian predators, particularly terns. Forage species are typically
silvery-sided, schooling fishes which spend a lot of their time near the surface of
the water overall depth strata. Of all the species captured during this study, eleven
qualified as significant forage. These species were northern anchovy, topsmelt,
slough anchovy, jack smelt, Pacific sardine, shiner surfperch, Pacific mackerel,
California grunion, deepbody anchovy, California halfbeaks, and striped mullet
(juveniles).

Over all Ecoregions for all five years, these eleven forage species averaged
3.15 (+£1.28) g/m’. Based on surface area, San Diego Bay contained, on average
about 139 metric tons (mt) of these important forage species. The standing stock
ranged from a low of about 22 mt in the South Ecoregion to a high of 43 mt in
the North Ecoregion (Table 13).

In the North Ecoregion, northern anchovy ranked first among the forage species
in contributing an average of nearly 14 mt over the study period followed by
topsmelt (10.1 mt), Pacific sardine (7.9 mt), and jacksmelt (4.9 mt). The standing
stock of the North-Central region was dominated, again, by northern anchovy
(13.0 mt), followed by slough anchovy (8.5 mt) and topsmelt (6.3 mt). Slough
anchovy (22.6 mt), topsmelt (5.5 mt), and shiner surfperch (5.2 mt) made up the
bulk of the forage in the South-Central Ecoregion while slough anchovy (10.2
mt), topsmelt (5.4 mt) and jack smelt (3.3 mt) dominated the South Ecoregion.

Based on a conservative, hypothetical, ecological efficiency of 1%, overall, San
Diego Bay has the potential to support about 1.4 mt of terns.

FISH ASSEMBLAGES OF SAN DIEGO BAY VT.

Table 11. Best estimate of numerical densities (No./m?2) and estimated stock size for the most
abundant fish species taken from San Diego Bay, as a whole, from July 1994 to April 1999.

BEST ESTIMATE OF DENSITY (No/m?)

COMMON NAME STRATA WTD STOCK
i N Cc MEAN Est. No.

northern anchovy 0.014 1.434 0.148 0.876 42,533,776
slough anchovy 0.067 0.566 0.109 0.368 17,868,784
topsmelt 1-750 O22 0.049 01210 —-10/2011,;738
Pacific sardine 0.002 0.074 0.058 0.065 3,148,496
arrow goby 1.414 0.005 0.000 0.059 2,876,938
shiner surfperch 0.003 0.067 0.000 0.039 1,873,634
California grunion 0.005 0.035 0.002 0.021 1,006,501
shadow goby 0.485 0.002 0.000 0.020 992,253
bay pipefish 0.033 0.021 0.000 0.013 651,421
giant kelpfish 0.004 0.023 0.000 0.013 648,728
jacksmelt 0.266 0.003 0.002 0.013 624,777
cheekspot goby 0.254 0.004 0.000 0.013 609,349
barred pipefish 0.034 0.016 0.000 0.011 513,060
round stingray 0.001 0.007 0.004 0.006 PATONG)
spotted sand bass 0.000 0.006 0.001 0.003 169,452
barred sand bass 0.000 0.004 0.002 0.003 133,803
California halibut 0.015 0.001 0.001 0.002 78,725
deepbody anchovy 0.000 0.002 0.000 0.001 63,451
bay blenny 0.006 0.002 0.000 0.001 58,865
kelp bass 0.000 0.002 0.000 0.001 47,300
queenfish 0.000 0.001 0.001 0.001 45,933
California killifish 0.017 0.000 0.000 0.001 32,785
salema 0.000 0.001 0.000 0.001 32,514
black surfperch 0.000 0.001 0.000 0.001 26,967
Pacific mackerel 0.000 0.001 0.000 0.001 26,116
diamond turbot 0.006 0.000 0.000 0.000 24,004
California halfbeak 0.003 0.000 0.000 0.000 21,394
dwarf surfperch 0.001 0.001 0.000 0.000 20,286
bonefish 0.002 0.000 0.000 0.000 11,196
California barracuda 0.000 0.000 0.000 0.000 10,828
black croaker 0.000 0.000 0.000 0.000 10,220
striped mullet 0.004 0.000 0.000 0.000 9,221
47 additional species 0.009 0.003 0.001 0.003 127,138
TOTAL 4.396 2.494 0.378 1.745 84,776,769

Fisheries Species.—Eight species of fish were captured that can be characterized
as fisheries species important to the recreational and/or commercial (RC) catch in
southern California waters. Ranked according to mean biomass density, these spe-
cies were northern anchovy, spotted sand bass, Pacific sardine, California halibut,
barred sand bass, Pacific mackerel, shortfin corvina, and yellowfin croaker.

Over all Ecoregions for all five years, these eight, RC species averaged 2.40
(+£1.14) g/m’. Based on a surface area of approximately 4858 ha, San Diego Bay
contains, on average about 104 metric tons (mt) of these important RC species.
The standing stock of RC species ranged from a low of about 15 mt in the South
Ecoregion to a high of 31 mt in the North Ecoregion (Table 13).

In the North Ecoregion, northern anchovy ranked first among the RC species
in contributing an average of nearly 14 mt over the study period followed by

78 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

Table 12. Best estimates of biomass densities (g/m?) and estimated stock size for the most abundant
fish species taken from San Diego Bay, as a whole, from July 1994 to April 1999.

BEST ESTIMATE OF DENSITY (g/m?)

COMMON NAME STRATA WTD STOCK STOCK
I N Cc MEAN Est. No. metric tons

northern anchovy 0.010 1.628 0.356 1.067 51,836,937 51.8
spotted sand bass 0.007 1.638 0.253 1.033 50,180,537 50.2
round stingray 0.051 1.284 0.714 1012 49,181,019 49.2
topsmelt 0.675 1.054 0.330 0.756 36,745,334 36.7
slough anchovy 0.073 0.984 0.475 0.749 36,385,765 36.4
bat ray 0.000 0.540 0.303 0.426 20,680,619 20.7
Pacific sardine 0.009 0.294 0.301 0.286 13,878,325 13.9
shiner surfperch 0.043 0.481 0.001 0.276 13,424,822 13.4
shovelnose guitarfish 0.000 0.423 0.029 0.252 12,262,405 yeas:
jacksmelt 0.006 0.200 0.216 0.198 9,623,670 9.6
California grunion 0.059 0.208 0.003 0.122 5,944,893 5.9
California halibut 0.031 0.093 0.159 0.117 5,660,609 SF
barred sand bass 0.006 0.075 0.181 Onis 5,511,344 55
giant kelpfish 0.034 0.180 0.004 0.106 5,132,391 5a
Pacific mackerel 0.000 0.112 0.044 0.081 3,931,394 3.9
shortfin corvina 0.000 0.058 0.051 0.053 2,569,953 2.6
black surfperch 0.003 0.074 0.001 0.043 2,082,049 Zan
yellowfin croaker 0.001 0.055 0.014 0.037 1,779,889 1.8
diamond turbot 0.083 0.014 0.057 0.033 1,610,660 1.6
queenfish 0.000 0.041 0.002 0.024 1,186,484 12
black croaker 0.000 0.019 0.034 0.024 1,167,441 122
grey smoothhound 0.003 0.023 0.013 0.018 898,173 0.9
jack mackerel 0.000 0.029 0.000 0.016 798,093 0.8
California butterfly ray 0.000 0.019 0.013 0.016 781,311 0.8
California needlefish 0.003 0.020 0.008 0.015 708,700 0.7
California barracuda 0.000 0.008 0.024 0.014 673,435 0.7
spotted turbot 0.000 0.005 0.026 0.013 628,138 0.6
salema 0.000 0.020 0.000 0.011 548,458 0.5
Calfornia corbina 0.000 0.019 0.000 0.011 535,960 0.5
deepbody anchovy 0.001 0.017 0.000 0.010 464,102 0.5
bay blenny 0.013 0.014 0.000 0.008 409,919 0.4
striped mullet 0.004 0.011 0.004 0.008 384,765 0.4
46 additional species 0.265 0.110 0.067 0.099 4,819,018 4.8

TOTAL 1.380 9.749 3.684 7.049 342,426,611 342.4

Pacific sardine (7.9 mt), and spotted sand bass (4.3 mt). The standing stock of
the North-Central region was dominated, again, by northern anchovy (13.0 mt),
followed by spotted sand bass (11.4 mt) and barred sand bass (1.3 mt). Spotted
sand bass (19.4 mt), Pacific sardine (2.8 mt), and California halibut (2 mt) made
up the bulk of the fisheries standing stock in the South-Central Ecoregion while
spotted sand bass (19.4 mt), Pacific sardine (2.8 mt) and yellowfin croaker (0.8
mt) dominated the South Ecoregion.

Southern Species Unique to San Diego Bay

During the study period eight fish species were taken that can be described as
southern or “‘Panamic Province”’ species including California halfbeaks (Hypor-
hamphus rosae), bonefish (Albula vulpes), California needlefish (Strongylura ex-
ilis), shortfin corvina (Cynoscion parvipinnis), Pacific seahorse (Hippocampus in-

FISH ASSEMBLAGES OF SAN DIEGO BAY 79

Table 13. Best estimates of biomass densities and standing stocks for forage species only and
fisheries species only. Estimates are for each depth strata within each Ecoregion of the San Diego
Bay.

FORAGE FISH SPECIES

BEST ESTIMATE OF DENSITY (g/m?)

STRATA WTD STAND.
ECOREGION N Cc MEAN STOCK (kg) mt
NORTH 0.8976 8.5278 2.4428 4.3337 42,557 43
NORTH-CENTRAL 1.0586 6.4966 2.9132 4.1821 33,792 34
SOUTH-CENTRAL 0.8767 2.5911 —- 1.2028 2.0399 40,899 41
SOUTH 0.7618 2.3416 0.3697 2.0454 21,763 22
TOTAL 139,011 139

RECREATIONAL/COMMERCIAL FISH SPECIES

BEST ESTIMATE OF DENSITY (g/m?)

STRATA WTD STAND.
ECOREGION N Cc MEAN STOCK(kg) mt
NORTH 0.08256 5.98068 2.01888 3.18991 31,325 31
NORTH-CENTRAL 0.08203 6.47010 1.98423 3.59375 29,038 29
SOUTH-CENTRAL 0.08484 1.85872 0.90180 1.46101 29,293 29
SOUTH 0.01123 1.52618 0.68564 1.37157 14,594 15

TOTAL 104,249 104

gens), California butterfly ray (Gymnura marmorata), banded guitarfish (Zapteryx
exasperata), and red goatfish (Pseudupeneus grandisquamous). In addition, four
more southern species (green jack, Caranx caballus; middling thread herring,
Opisthonema medirastre; Pacific sierra, Scomberomorus sierra; scalloped ham-
merhead, Sphyrna lewini) were collected by gill nets in the Ocean Resource En-
hancement and Hatchery Program (OREHP) sampling program conducted by
Mike Shane of Hubbs-Sea World Research Institute in the same general time
period. All of these species are commonly encountered further south in the Eastern
Subtropical and Tropical Pacific. Southern California is listed as the extreme
northern end point of the geographical ranges of each of these species. In fact,
the occurrence of the single specimen of the red goatfish represented the first
record of this species recorded in California waters. The southern portion of San
Diego Bay undoubtedly acts as a refuge for these warm water species. Three of
these, the California halfbeak, California needlefish and Pacific seahorse were
encountered throughout the study period (Figure 16) while the remaining five
occurred in greatest abundance during and just after the El Nino evident of 1997—
98. Bonefish recruited heavily into the southern sections of the bay beginning in
January 1998 and peaked April 1998. Bonefish leptocephalus larvae were cap-
tured in the intertidal zones in January and April 1998. These leptocephali meta-
morphosed into juveniles which were abundant in July and October of the same
year.

80 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

Hyporhamphus rosae

Albula vulpes

Strongylura exilis

Cynoscion parvipinnis

3
3
i
=
a
gee
Number

Zapteryx exasperata

Pseudupeneus grandisquamous

Fig. 16. Abundance of “‘Panamic Province”’ or southern species captures in San Diego Bay from
July 1994 to April 1999.

Effects of 1997-98 El Nino

The greatest, detectable impact of the 1997—98 El Nino event on the fish as-
semblages of San Diego Bay was the generally low abundance of schooling,
planktivorous species, including northern anchovy, topsmelt, slough anchovy, sar-
dine, and shiner surfperch (the five most abundant species). In fact, the northern
anchovy was virtually absent during 1997. Of the most abundant schooling fishes,
topsmelt and slough anchovy seemed to be least affected by the El Nino event.
Overall, the abundance of these planktivorous species was significantly and neg-
atively correlated (log(n + 1), r = —0.86, df = 4, p < 0.05) with summer-fall
(July—October) surface water temperature over the entire 1994-1999 sampling
period.

The quantitative impact of the El Nino on the total number of fishes in San
Diego Bay can be approximated using the regression model:

IN 232 le i 22

where N = predicted number and T = mean surface temperature. This equation
was based on the relationship between abundance of planktivorous species and
surface water temperature for the non- El Nino years of the study. Based on this
equation, the total catch of all species in San Diego Bay was 50,000 to 55,000
individuals lower in July and October 1997 than would be predicted for a “‘nor-
mal”’ temperature year.

Another important effect that can probably be attributed to the ENSO event
was the recruitment and/or occurrence of the southern species mentioned previ-
ously.

FISH ASSEMBLAGES OF SAN DIEGO BAY 81

Discussion

A total of 78 species of fish were captured in the five years of sampling in San
Diego Bay. This total approaches the 89 species predicted from the species-area
relationship developed by Horn and Allen (1976). A number of relatively rare,
large, and mobile species were undoubtedly missed by this quantitative sampling
protocol. The aforementioned OREHP gill net survey (June 1996 through August
1999) yielded eight additional species which were not taken in the current sam-
pling program. The addition of these species (green jack, Caranx caballus; pile
surfperch, Damalichthys vacca; middling thread herring, Opisthonema mediras-
tre; white surfperch, Phanerodon furcatus; Pacific sierra, Scomberomorus sierra;
scalloped hammerhead, Sphyrna lewini; angel shark, Squatina californica; leopard
shark, Triakis semifasciata) brings the total up to 86 species, even closer to the
predicted number of 89 species.

Two, introduced species of Japanese gobies were also captured during the study.
The yellowfin goby (Acanthogobius flavimanus) was well represented in the sam-
ples (n = 34) while a single specimen of the chameleon goby (Tridentiger tri-
gonocephalus) was captured in the eelgrass bed in the South-Central Ecoregion
(Station 3).

Species richness by station in San Diego Bay was comparable, if not higher
than values obtained from other southern California bays, estuaries, and harbors.
The northern San Diego Bay stations | and 2 (No. spp = 69 and 55) had similar
species richness to multiple-gear sampling studies in Los Angeles Harbor and
Lower Newport Bay. Allen et al. (1983) captured 65 fish species in the Cabrillo
Beach area of western Los Angeles Harbor in 1979. Marine Ecological Consul-
tants (1988) reported 69 fish species in the area covering most of outer Los
Angeles Harbor in 1986—87. Allen (1976) sampled a total of 65 species from
Newport Bay in 1974-75 in a sampling strategy that included stations from
throughout the upper and lower bay.

The southern San Diego Bay stations yielded slightly higher species richness
(Station 3, 49 species; Station 4, 52 species) than comparable studies in two other
bay/ estuaries in southern California, Mugu Lagoon and upper Newport Bay. Onuf
and Quammen (1983) caught a total of only 28 fish species from the small,
shallow embayment of Mugu Lagoon. Horn and Allen (1981) reported 46 species
captured in a comparable, multiple-gear sampling design in Upper Newport Bay
in 1978. Furthermore, Allen (1988) reported 41 species from upper Newport Bay
in 1986-87.

Total Shannon-Weiner diversity (H’) for the San Diego Bay stations in 1994—
99 ranged from values of 2.05 to 2.32. These H’ values were intermediate to the
somewhat lower values reported from upper Newport Bay (1.71 from 1978; 1.94
from 1986-87) and the slightly higher values in Los Angeles Harbor and lower
Newport Bay (Cabrillo, H’ = 2.39; outer LA Harbor, H’ = 2.69; lower Newport
Bay, H’ = 3.09). The lower H’ values in upper Newport Bay reflect the numerical
dominance of a single species, the topsmelt in the catches. The intermediate values
of the San Diego Bay stations were the result of numerical dominance of three
species, northern anchovy, slough anchovy and topsmelt.

The fish assemblages of San Diego Bay represent a blend of those normally
associated with harbors and bay/estuaries within the Southern California Bight

82 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

t= CABRILLO
Oe ine we
de
14°) SDB949S1
BS ie
SDB949S2
> MUGU
E en ereee
” UNB78 |
LL NB7475 |
|
> SDB949S3
SDB949S4
m ' |
0.0 0.2 0.4 0.6 0.8 1.0 1.2

Linkage Distance

Fig. 17. Cluster of Southern Californian harbor (H), bay and estuarine (BE) habitats based on fish
faunal relationships.(Cabrillo = Cabrillo Beach, Los Angeles Harbor; POLA = Port of Los Angeles;
Mugu = Mugu Lagoon; NB7475 = Newport Bay study 1974—75; UNB = upper Newport Bay study
1978; UNB8687 = upper Newport Bay study 1986—87; SDB9499S = Present study for stations 1—
4).

(Allen, 1985). San Diego Bay stations | and 2 cluster with the fish assemblages
from previous, comparable studies in southern California harbors (Figure 17),
while stations 3 and 4 are more closely associated with the assemblages in the
bay/estuaries of southern California. Therefore, San Diego Bay represents a large,
unique environment within the Southern California Bight combining elements of
two major types of habitats, namely harbor-nearshore soft bottom (HNSB) and
bay/estuary (BE) (cf. Allen, 1985).

Allen (1980) conducted the only comparable study utilizing the best estimate
process in upper Newport Bay in 1978. Using a similar sampling design, Allen
(1980) calculated an overall biomass density of 4.1 g/m? for the littoral (intertidal)
fish assemblages in upper Newport Bay. This value was about two-thirds of the
value of 6.3 g/m? derived from the best estimate process in the same study. It is
important to note that the overall biomass density estimated herein for San Diego
Bay (7.05 g/m’) exceeded even that from the widely acknowledged, highly pro-
ductive environment of upper Newport Bay.

Within individual Ecoregions of San Diego Bay, the intertidal areas contained,
in general, the highest numerical densities with the North-Central and South re-
gions with best estimates of over 6 indiv./m? overall. This was undoubtedly due
to the large number of juvenile fishes which recruit to and occupy these warm,
productive areas, particularly in the spring. The nearshore habitat supported, by
far, the highest biomass densities of fish over the study period. The highest den-
sities were recorded in the North and North-Central ecoregions due primarily to
large catches of northern anchovy and spotted sand bass in the summer. The
relatively high biomass density found in the South Ecoregion was due mainly to
large catches of round stingrays, spotted sand bass, and slough anchovies.

In summary, the fish assemblages of San Diego Bay were found to be diverse,
abundant, seasonal, and highly productive particularly for young-of-the-year fish-
es. The bay itself presents a unique combination of harbor, nearshore soft bottom,

FISH ASSEMBLAGES OF SAN DIEGO BAY 83

and bay/estuarine habitats which each contribute unique sets of species to the
overall assemblage. One of these is a group of 12 species which are indigenous
to the bays and estuaries of southern California. South San Diego Bay represents
a crtical habitat for these unique bay/estuarine species whose habitats have dis-
appeared at an alarming rate during the last half century. The extensive shallow
water habitat and eelgrass beds also support a very high standing stock of mid-
water, schooling fishes, such as northern anchovies, slough anchovies and topsmelt
which, in turn, serve as an important forage resource for both marine birds and
larger predatory fishes. In addition, the generally warm and hypersaline waters of
south San Diego Bay offer a warm water refuge for a number of southern, “‘Pan-
amic”’ province fish species making it unique among all other southern California
embayments.

Acknowledgments

We are greatly indebted to Mitchell Perdue of the U.S Navy’s Facilities Engi-
neering Command, Southwest Division and Robert Hoffman of the National Ma-
rine Fisheries Service who oversaw the project in its entirety and lowered many
administrative hurdles. This work could not have been completed without the
efforts of former graduate students, Tim Hovey and Holly Harpham, who acted
as project managers in the early years of the investigation. The following CSUN
graduate and undergraduate students were also instrumental in the collection of
field data: Cheryl Baca, Greg Benavides, Brian Buaas, Craig Campbell, Colin
Chapman, Erik Forsman, Shoshanna Grunwald, Mara Morgan, Jesse Rivera,
Becky Rudy, Dennis Rutnam, John Smith, Greg Tranah, and Karin Wisenbaker.
The crew of the California State Univesity’s R/V Yellowfin, Capt. Jim Cvitanovich,
Dennis Dunn, Jr., Todd Chapman, Paul Skaar, and Dan Warren, worked tirelessly
during each demanding sampling period over the five years, particularly on purse
seine duty. Finally, we also thank Dan Pondella, Matt Craig, and Jana Cobb of
the Vantuna Research Group of Occidental College for their timely, valuable
assistance in the field sampling program. This research was supported under con-
tract from the Department of the Navy and was funded by the Navy and the
Unified Port of San Diego.

Literature Cited

Allen, L.G. 1976. Abundance, diversity, seasonality and community structure of fish populations in
Newport Bay, California. M.A. Thesis. Calif. State Univ., Fullerton, 108 p.

. 1980. Structure and Function of the littoral fish assemblage of upper Newport Bay, California.

Ph.D. Dissertation, University of Southern California, 175 pp.

. 1982. Seasonal abundance, composition, and productivity of the littoral fish assemblage in

upper Newport Bay, California. U.S. Fish. Bull., 80(4):769-—790.

. 1985. A habitat analysis of the nearshore marine fishes from southern California. Bull. So.

CalmAcad*Set:,*84(3)2°133=155:

. 1988a. Recruitment, distribution, and feeding habits of young-of-the-year California halibut

(Paralichthys californicus) in the vicinity of Alamitos Bay- Long Beach Harbor, California,

1983-1985. Bull. So. Calif. Acad. Sci., 87(1): 19- 30.

. 1988b. Results of a two-year monitoring study on the fish populations in the restored, up-

permost portion of Newport Bay, California; with emphasis on the impact of additional estuarine

habitat on fisheries-related species. Final Report for Contract to the National Marine Fisheries

Service, NOAA, 60 pp.

, M.H. Horn, EA. Edmands II and C. Usui. 1983. Structure and seasonal dynamics of the fish

84 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

assemblage in the Cabrillo Beach area of the Los Angeles Harbor, California. Bull. So. Calif.
Acad. Sci. 82(2), 47-70.

Cronin, L.E. and A.J. Mansueti. 1971. The biology of the estuary, p. 14—39. In: PRA. Douglas and
R.H. Stroud (editors), A symposium on the biological significance of estuaries, Sport Fish. Inst.,
Wash., D. C.

Duffy, JM. 1987. A review of the San Diego Bay striped mullet, Mugil cephalus, fishery. Calif. Dept.
Fish Game, Mar. Res. Tech. Rep. No. 56, 10 pp.

and H.J. Bernard. 1985. Milkfish, Chanos chanos (Forsskal, 1775), taken in southern Cali-
fornia adds new family (Chanidae) to the California marine fauna. Calif. Fish Game, 71(2):
122-125.

Ford, R.E 1968. Marine organisms of South San Diego Bay and the ecological effects of power station
cooling water. A Pilot study conducted for San Diego Gas and Electric Co., San Diego, En-
vironmental Engineering Laboratory Tech. Rept. on Contract C-188. 278 pp.

. 1985. Species composition, distribution and abundance of fishes along the southern shore of

Coronado Cays, San Diego Bay, in October 1985. Prepared for David D. Smith and Associates,

Inc., San Diego, and Coronado Landmark, Inc., Irvine. December 8, 1985. 9 pp.

. 1985. Species composition, distribution and abundance of fishes along the southern shore of
Coronado Cays, San Diego Bay, in February 1986. Prepared for David D. Smith and Associates,
Inc., San Diego, and Coronado Landmark, Inc., Irvine. April 10, 1986. 10 pp.

Haedrich, R.L. and C.A.S. Hall. 1976. Fishes and estuaries. Oceanus, 19(5):55—63.

Hoffman, R.S. 1986. Fishery utilization of eelgrass (Zostera marina) beds and non- vegetated shallow
water areas in San Diego Bay. National Oceanic and Atmospheric Administration, National
Marine Fisheries Service, Southwest Region, Administrative Report SWR-86—4. 29 pp.

. 1995. Data summary for Mission Bay/San Diego Bay beach seine study, January 1988 to
July 1994. National Oceanic and Atmospheric Administration, National Marine Fisheries Ser-
vice, Southwest Region, Long Beach.

Horn, M.H. 1980. Diversity and ecological roles of noncommercial fishes in California marine habitats.
CalCOFI, 21:37—47.

. and L.G. Allen. 1976. Numbers and faunal resemblance of marine fishes in California bays

and estuaries. Bull. So. Calif. Acad. Sci., 75(2): 159-170.

. and . 1981. Ecology of fishes in upper Newport Bay, California: seasonal dynamics

and community structure. Calif. Fish Game, Tech. Rep., 45: 101 p.

and . 198la. A review and synthesis of ichthyofaunal studies in the vicinity of Los

Angeles and Long Beach Harbors, Los Angeles County, California. Final Report, U.S. Fish

and Wildlife Service, Ecological Services, Laguna Niguel, CA. 96 pp.

and . 1981b. Ecology of fishes in Upper Newport Bay, California: seasonal dynamics
and community structure. Calif. Dept. Fish Game, Mar. Res. Tech. Rep. No. 45, 102 pp.

Jones, A.T., P. Dutton, and R.E. Snodgrass. 1988. Reoccurrence of the Pacific seahorse, Hippocampus
ingens, in San Diego Bay. Calif. Fish Game, 74(4): 236—238.

Kjelson, M.A. and D.R. Colby. 1977. The evaluation and use of gear efficiencies in the estimation of
estuarine fish abundance, p. 416—424. In: M. Wiley (ed.), Estuarine Processes, Vol. 2. Academic
Press, New York.

and G. N. Johnson. 1978. Catch efficiencies of a 6.l-meter otter trawl for estuarine fish
populations. Trans. Am. Fish Soc. 107(2): 246—254.

Lea, R.N., C.C. Swift, and R.J. Lavenberg. 1988. Records of Mugil curema Valenciennes, the white
mullet, from southern California. Bull. So. Calif. Acad. Sci., 87(1): 31-34.

and R.H. Rosenblatt. 1992. The cortez grunt (Haemulon flaviguttatum) recorded from two

embayments in southern California. Calif. Fish Game, 78(4): 163-165.

and H.J. Walker, Jr. 1995. Record of the bigeye trevally, Caranx sexfasciatus, and Mexican
lookdown, Selene brevoorti, with notes on other carangids from California. Calif. Fish Game,
81(3): 89-95.

Lockheed Center for Marine Research. 1979. Biological reconnaissance of selected sites of San Diego
Bay. Submitted to San Diego Port District, Environmental Management. 77 pp.

Lockheed Ocean Sciences Laboratory. 1983. Distribution and abundance of fishes in central San Diego
Bay, California: a study of fish habitat utilization. Prepared for Department of Navy, Naval
Facilities Engineering Command under Contract No.'N62474-82-C- 1068. 38 pp.

Marine Ecological Consultants (MEC). 1988. Biological Baseline and ecological evaluation of existing

FISH ASSEMBLAGES OF SAN DIEGO BAY 85

habitats in Los Angeles Harbor and adjacent waters. Vol 1, Executive Summary, Final Report
to Port of Los Angeles, San Pedro, CA, 54 pp.

Onuf, C.P. and M.L. Quammen. 1983. Fishes in a California coastal lagoon: effects of major storms
on distribution and abundance. Mar. Ecol. Progr. Ser., 12: 1—14.

San Diego Gas & Electric Co. 1980. South Bay Power Plant cooling water intake system demonstration
(in accordance with Section 316(b), Federal Water Pollution Control Act Amendment of 1972).
Prepared by San Diego Gas & Electric Co. and the Lockheed Center for Marine Research, San
Diego, for the San Diego Regional Water Quality Control Board.

San Diego Unified Port District. 1980. Final Environmental Impact Report on the Port Master Plan,
San Diego Unified Port District. Environmental Management Department, San Diego Unified
Port District, San Diego, CA. February 1980.

. 1990. South San Diego Bay Enhancement Plan, Volume One/ Resources Atlas, Marine eco-

logical characterization, bay history and physical environment. prepared by Michael Brandon

Associates, Inc., San Diego.

Accepted for publication 13 May 2001

Bull. Southern California Acad. Sci.
101(2), 2002, pp. 86—102
© Southern California Academy of Sciences, 2002

An evaluation of the distribution and abundance of Common
Ravens at Joshua Tree National Park

William I. Boarman! and Sharon J. Coe?

'U.S. Geological Survey, Western Ecological Research Center,
5745 Kearny Villa Drive, Suite M, San Diego, CA 92123
-Department of Biology, University of California, Riverside, California 92521

Abstract.—We located and evaluated data from the past 100 years to assess the
historical and contemporary abundance and distribution of Common Ravens (Cor-
vus corax) at and near Joshua Tree National Park in southern California. We found
evidence to support the hypothesis that numbers and distribution of this species
have increased in the park in the last 50 years. Increases in raven numbers pose
a potential threat to populations of Desert Tortoise (Gopherus agassizii), as ju-
venile tortoises are known prey of the Common Raven. We obtained additional
data that support the hypotheses that raven densities may be higher in the Mojave
Desert than the Colorado Desert, and that densities appear to be lower in regions
with few roads. Some of the largest concentration areas for ravens are found at
landfills in the Mojave Desert.

The Common Raven (Corvus corax) is native to the deserts of southern Cali-
fornia but its abundance in the Mojave Desert has grown substantially in recent
years. An analysis of Breeding Bird Survey (BBS) data for the Sonoran and
Mojave Deserts (Boarman and Berry 1995) showed that raven populations in-
creased 450—1000% over a recent 24-year period. Such increases have raised
concerns among wildlife biologists and resource managers because ravens are
known to prey on juvenile Desert Tortoises (Gopherus agassizii), a species fed-
erally-listed as Threatened in the Southwest (U.S. Fish and Wildlife Service
1994). Increases in Common Raven densities in desert areas have been implicated
as contributing to the decline of some Desert Tortoise populations (Bureau of
Land Management 1990, Boarman 1993, U.S. Fish and Wildlife Service 1994).
Ravens prey on avian species that are declining, as well. This includes predation
of eggs of the California condor (Gymnogyps californianus; Snyder et al. 1986),
of the state- Endangered California least tern (Sterna antillarum browni; Avery
et al. 1995), and of the greater sandhill crane (Grus canadensis tabida; Littlefield
and Thompson 1987), a California state-listed Threatened species. Ravens prey
on eggs and chicks of the western snowy plover (Charadrius alexandrinus ni-
vosus) on the California coast (pers. comm. Gary Page, Point Reyes Bird Obser-
vatory), a species whose coastal nesting populations are federally-listed as Threat-
ened.

Increases in Common Raven numbers have been attributed to an increase in
human occupation in the region (Boarman and Berry 1995). One anthropogenic
resource used by ravens in the deserts of California is landfills. Ravens use land-
fills as foraging sites, including the consumption of organic materials exposed
along the active face of landfills (FaunaWest Wildlife Consultants 1991). Imple-

86

RAVEN ABUNDANCE AT JOSHUA TREE NATIONAL PARK 87

Twentynine

Mountains

Future location
of Eagle Mountain
Landill

Ki

eys View Pinto Basin Road

Mine Road
Cottonwood
Springs
South
Entrance

Cactus
City
area

/\/ Roads and highways
C] Park boundary A

9 2,0 40 Kilometers ~

Fig. 1. Joshua Tree National Park and immediate surroundings.

mentation of a proposed large solid waste landfill in southeastern California ad-
jacent to Joshua Tree National Park (JTNP) is considered to be a factor that could
promote the establishment of additional populations of Common Ravens in the
region, and/or increases in existing populations, which could further threaten the
Desert Tortoise (Fig. 1). The proposed landfill, Eagle Mountain Landfill (EML),
is currently in litigation. Should it be implemented as it was configured prior to
legal proceedings, it is expected to receive up to 1,814 metric tons (1 metric
ton=1000 kg) of garbage per day.

Resource managers at JTNP asked us to obtain and review information on the
abundance and distribution of Common Ravens in and near the park as baseline
information to be used in evaluating whether raven populations increase should
EML be implemented (Boarman and Coe 2000a, 2000b). We located and evalu-
ated both contemporary and historic data to assess what was known about Com-
mon Raven abundance and distribution.

Joshua Tree National Park consists of 794,000 hectares of Mojave Desert and
Sonoran (Colorado) Desert plant communities. Areas that currently comprise
JTNP were established as a National Monument in 1936. Through the California
Desert Protection Act of 1994, the monument increased by 94,670 hectares and
acquired National Park status. We refer to observations that were made within
either the monument or park as having occurred in JTNP.

Methods

We searched for published and unpublished sources of information describing
Common Raven abundance and distribution in and near JTNP. We obtained un-

88 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

published data such as field notes, species lists, and reports with the assistance of
JTNP staff within the Resources Management and Interpretation Divisions. We
also contacted JTNP volunteers and local experts, who held first-hand knowledge
of ravens at the park, and obtained additional field notes from them. We acquired
unpublished Breeding Bird Atlas (BBA) data for the two counties where JTNP
is located (San Bernardino and Riverside Counties). We also contacted museums
(California Academy of Sciences [CAS], Los Angeles County Museum of Natural
History [LACMNH], San Bernardino County Museum [SBCM], San Diego Nat-
ural History Museum [SDNHM], Museum of Vertebrate Zoology [MVZ], and
Western Foundation of Vertebrate Zoology [WFVZ]) for locations and dates of
skins and eggs that had been collected in the region.

Results and Discussion

We located more than 13 sources of information pertaining to the occurrence
of Common Ravens in JTNP and its vicinity, most of which pertained to the past
50 years (Table 1). The majority of data were unpublished records and pertained
to observations within JTNP, although some included observations outside the
park’s boundaries.

Prehistoric information

Evidence from the fossil record indicates that Common Ravens were present
in California deserts in prehistoric times. The species is known from Late Qua-
ternary period deposits in San Bernardino County (Jefferson 1991). These include
deposits that date back 100,000 to 4,000,000 years before present (BP) from the
Mitchell Caverns located in the Providence Mountains (approximately 98 km
northeast of JTNP). Raven fossils, whose age was estimated using radiometric
dating to be approximately 12,500 years BP, are also known from Schuiling Cave
in the Newberry Mountains (approximately 85 km northwest of JTNP; Jefferson
LOB):

Historical (pre-1940) observations

Historical observations of Common Ravens in and near JTNP, and in southern
California in general, helped us to estimate their densities prior to contemporary
levels of human occupancy. Scant information is available about the abundance
of the species in and adjacent to JTNP at the turn of the twentieth century. One
of the earliest sources was the Death Valley Expedition of 1891 (Fisher 1893).
Common Ravens were seen in Death Valley by every party that visited there
between early January and late June. They were also seen in the Mojave Desert
(location not provided) in early January, and in the Antelope Valley in June. Little
information on the abundance of the species can be gleaned from this account.
However, an observation of a minimum of 40 individuals foraging on grasshop-
pers in the Antelope Valley in June indicates that relatively large groups occurred
at least occasionally. The report also stated that Common Ravens were believed
to breed in the desert ranges of southern California and Nevada.

Van Rossem (1911) observed Common Ravens ‘‘about every day usually in
pairs” in the winter of 1910/1911 in the Salton Sea region (Colorado Desert); the
northern portion of the Salton Sea lies approximately 19 km from the southern
border of JTINP. The species may have been more common to the north of the

89

RAVEN ABUNDANCE AT JOSHUA TREE NATIONAL PARK

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park, as Lamb (1912) reported it in the Mojave River Valley (102 km north of
JTNP) in 1910 and 1911 as “‘common at all times everywhere, nesting on cliffs
in the mountains.’’ Gilman (1935) observed as many as 40 Common Ravens at
one time at a wildlife feeding station at Death Valley National Park during ob-
servations made between October 1933 and May 1934 where he also reported a
nest in a cliff. The earliest record from Joshua Tree National Park was an obser-
vation of a pair of Common Ravens in 1935 at Twentynine Palms Oasis, an area
that lies within current park boundaries (Carter 1937). No indication of the abun-
dance of the species was provided.

Few specimens from this time period and this region exist in museum collec-
tions. Therefore, little information about Common Raven distribution was gained
beyond what we obtained from other sources; no information on abundance was
acquired. The specimen taken closest to the park boundaries was 29 km southwest
of the park border, collected in Mecca (Riverside County) in March 1908 (MVZ
# 770). A specimen collected in “‘Walters, Imperial County” in January 1890 is
considered to be from what is currently known as Mecca (SDNHM # 748; pers.
comm. Philip Unitt). Two ravens were collected approximately 80 km northwest
of JTNP in Victorville (San Bernardino County) in March 1907 (MVZ # 206)
and in March 1914 (MVZ # 24573). All other specimens are from greater than
80 km from JTNP.

Distribution since 1940

There is an increasing amount of information about bird populations, including
ravens, beginning in the mid-1900s. Grinnell and Miller (1944) cited portions of
the Mojave Desert as being a major center of abundance of the species in Cali-
fornia. However, Common Ravens do not appear on a species list for JTINP com-
piled in 1945 by Alden H. Miller that is on file at JTNP’s Interpretation Division.
Twenty years later, however, ravens were reported as a “‘sparse permanent resi-
dent” within JTNP (Miller and Stebbins 1964). What were populations like in
the twenty-year period between 1945 and 1964?

Fortunately, detailed observations of Common Ravens within JTNP were col-
lected in the mid-1950s by JTNP naturalist Charles Adams. He recorded species
of birds at 76 locations within JTNP between January 1955 and September 1956,
observing ravens in low numbers at 23 of the 76 locations. Most sightings were
of 2—3 individuals per location per visit; the largest number at one location on a
single visit was fourteen. It is possible that the absence of this species from
Miller’s 1945 bird list, in contrast to observations made by Adams roughly 10
years later, reflects an increase in size of the raven population in JTINP concom-
itant with an increase in human occupation and associated food resources in the
area.

To gain insight into changes in distribution, we evaluated recent data for ob-
servations at locations where Adams never reported ravens. While Adams re-
corded the birds that were present at Cottonwood Springs 38 times, he did not
record ravens as being present there (Fig. 1). Ravens have since been reported at
Cottonwood Springs in two different data sets: (1) observations by visitors to the
park reported on pre-printed index cards since the late 1950s (called Natural
History Field Observation Cards); and (2) observations made by staff and vol-
unteers of JTNP’s Resource Management Division on an ad hoc basis between

92 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

1990 and 1992 both in and near JTNP. In the first data set, ravens were reported
at Cottonwood Spring proper three times in 1978; in addition, one observation
was made at a nearby picnic area in 1973, and two observations were made at a
nearby residence in 1972 and 1973. In the second data set, the species was re-
corded once at the picnic area, and once on the road leading to the Spring. Sim-
ilarly, Adams recorded no ravens at a location known as Queen Valley despite
32 visits. More recently, ravens have been reported in this area, on Natural History
Field Observation Cards in 1978, and by the authors in 1999.

Both the Natural History Field Observation Cards and the JTNP’s Resource
Management Division observations support the hypothesis of current widespread
distribution of ravens within JTNP. The former data set contains sightings of
ravens at 29 locations, the latter contains 57 sightings at locations within and
adjacent to the JTNP. Miller and Stebbins (1964) also reported Common Ravens
as frequent scavengers along highways in the Coachella Valley in the Colorado
Desert, which abuts JTNP’s southern edge.

Breeding Bird Atlases are organized by volunteers and birding organizations
in many regions throughout the United States to determine the breeding range of
nesting species. In San Bernardino and Riverside Counties, BBA volunteers sur-
veyed atlas ““blocks’’ measuring 5 km square. This project confirms that Common
Ravens bred in JTNP in 1987, 1992, and 1994. Ravens were designated as “‘prob-
able”’ breeders in three blocks total (in 1987, 1988, and 1991), and as “*possible”’
breeders in four blocks total (in 1987 and 1991). That the species is a current
breeder at JTNP is not surprising given prior observations and the abundant suit-
able nesting habitat contained therein.

Densities in the Region

Virtually no information regarding densities of ravens is available for prior to
the mid-1900s. The earliest data of this kind are from Charles Adams’ work
(maximum numbers observed) and from Miller and Stebbins (1964) who reported
the species as “‘surprisingly scarce’? at JTINP compared to their widespread oc-
currence in the desert and near cliffs in the southwest.

We did obtain three sources of data on raven densities from the past 12 years.
The first source consisted of vehicle transect surveys conducted along paved high-
ways and improved dirt roads in four regions of the California deserts in 1988
and 1989 (Knowles et al. 1989, FaunaWest Wildlife Consultants 1991). Only one
portion of one of the routes occurred within JTNP, but three were located in its
vicinity. Landfills and sewage ponds were also surveyed, with three of the landfills
occurring near JTNP. Surveys were conducted over four 6-month periods. An
index of the number of ravens observed per 161 km was calculated because the
number of kilometers surveyed for each route varied. The portion of the route
located in JTNP, running from the South Entrance to the North Entrance, recorded
<1.0 to 6.0 ravens per 161 km over the four survey periods. For each of the three
routes in the vicinity of JTNP, the number of ravens per 161 km ranged from 0
to 5.0 for all four survey periods (Table 2). These values are small compared to
observations from routes in other parts of the study area (including areas with
greater human density), which ranged from one to 49 ravens per 161 km.

Numbers of ravens at landfills ranged from 0 to 210 (Table 3) and tended to
correspond positively with the numbers observed on road transects in their prox-

RAVEN ABUNDANCE AT JOSHUA TREE NATIONAL PARK 93

Table 2. Summary of Common Ravens observed on three road transects in the vicinity of JTNP
(Knowles et al. 1989, FaunaWest Wildlife Consultants 1991).

No. ravens No. km No. observed
Route observed traveled per 161 km
SC-1
Fall 1988 10 2309 oO
Winter 1989 18 2516 Le
Spring 1989 3 2541 <]
Summer 1989 O DS)33) 0
SC-2
Fall 1988 71 2297 5.0
Winter 1989 56 1911 Al
Spring 1989 44 2309 3
Summer 1989 14 DQG l
FC-2
Fall 1988 48 2202 35)
Winter 1989 a 2178 3:8
Spring 1989 By) 2217 2
Summer 1989 WS) 2210: 2

imity. Landfills supported the largest concentrations of ravens in all four regions
surveyed. Knowles et al. (1989) concluded that raven numbers observed at land-
fills were associated with the type, effectiveness, and frequency of waste burial
and not with the size of the landfill or the amount of garbage present. They also
concluded that ravens were more common in the Mojave Desert than the Colorado
Desert, that their distribution tended to be clumped on certain road segments rather
than being more or less evenly distributed, and that densities were highest near
areas populated by humans (Knowles et al. 1989).

Surveys conducted in the immediate vicinity of the proposed Eagle Mountain
Landfill provided even more recent information about raven densities (RECON
1994). Surveys were conducted in 1993 and 1994 on a monthly basis and included
both hour-long counts made at single locations and vehicle transects along three
routes (Table 4). The largest numbers of ravens observed at a point count location
was at an existing small-scale landfill approximately 8 km from the proposed
EML (range 5—40 individuals). The number observed on the three vehicle tran-

Table 3. Common Ravens observed at landfills in vicinity of Joshua Tree National Park (Know-
les et al. 1989, FaunaWest Wildlife Consultants 1989).

Total ravens observed on 12 twice-monthly visits

Fall Winter Spring Summer
Landfill 1988 1989 TOTAL 1989 1989 TOTAL
Landers Si 63 194 22\\0) 107 Si)
Amboy 1 0) 1 D O Z
Essex 40 31 vA 2 0) 2
Twenty-nine Palms 130 90 220 152 116 268
Desert Center 136 89 D2 62 7/ VS

Indio 64 3) W3) oh 54 85

94 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

Table 4. Common Ravens observed on surveys for the Eagle Mountain Landfill Biological Miti-
gation and Monitoring Program (RECON 1994).

Average Range of No. ravens
no. ravens no. ravens observed
Location observed observed per 1.61 km!

Point Stations

Desert Center Dump 20
Kaiser Townsite
Eagle Mountain Mine
Tower?

Joshua Tree?

- OF e

Vehicle Transects

Eagle Mtn. Road (from I-10 to Metropolitan Water District

pumping station; 11.3 km) l 0-10 0.17
Kaiser Road (from Desert Center to Eagle Mountain Mine;

16.1 km) 2 0-10 Ons
Interstate 10 (from Chiriaco Summit to Desert Center Road;

31.4 km) Z 0-7 0.01

' (Route length) < (12 surveys).
2 A tower located between Eagle Mountain Mine and Joshua Tree National Park.
> Overlooking Joshua Tree National Park from unspecified location.

sects was one, 15, and 17 ravens per 161 km, making the density on the last two
routes notably higher than those observed by Knowles et al. (1989) and
FaunaWest Wildlife Consultants (1991).

Knight and Kawashima (1993) surveyed linear right-of-ways by helicopter in
May and June of 1989. Their coverage of 45,000 square km of Mojave Desert in
San Bernardino County showed that ravens were more numerous on transects
near powerlines and highways than in control areas. Also, raven nests were sig-
nificantly more abundant along powerlines than along either highways or control
areas. On the eight transects located in or near JTNP, only one raven was ob-
served.

Raven Abundance In and Near JTNP

For monitoring changes in raven abundance over time, we considered stan-
dardized vehicle transects to be one of the best methods. Two such data sets exist:
the U.S.G.S. North American Breeding Bird Survey (BBS), and a program co-
ordinated by JTNP called Adopt-a-Raven Transects. The BBS has a vehicle route
length of 39.4 km. At 0.8 km intervals counts are made of all birds heard and
seen for a 3-minute period within a 0.4 km radius. Three BBS routes occur
entirely or partially within the park. The “‘Joshua Tree’’ route (#14131) has been
surveyed for 22 years since 1970, the “‘Cottonwood”’ route (#14088) for 20 years
since 1973, and the ‘“‘Cholla Garden’? route (#14907) for six consecutive years
beginning in 1995. The number of ravens recorded on the ‘Joshua Tree’’ route
has increased over time (Fig. 2). For example, before 1989, numbers of ravens
observed ranged between zero and nine. Since 1991, numbers observed have
increased to between 10 and 32 per survey. This route starts in the northwest
portion of JTNP and runs north through the town of Joshua Tree. We consider it
likely that these data reflect actual increases in numbers of ravens given the stan-

RAVEN ABUNDANCE AT JOSHUA TREE NATIONAL PARK 95

35

30

—v- Joshua Tree Route
—@— Cottonwood Route

29

20

15

10

No. of Common Ravens Observed

1965 1970 ASTD 1980 1985 1990 IES 2000 2005

Year

Fig. 2. Common Ravens observed on the “Joshua Tree’? BBS Route between 1970 and 2000, and
on the ““Cottonwood” BBS Route between 1973 and 1997.

dardized survey methods. The increases in numbers observed may be correlated
with the fact that the route is adjacent to, and travels through, the town of Joshua
Tree, which has increased in human population size in the last 30 years; between
1970 and 1990, Joshua Tree’s population more than tripled from 1,211 to 3,898
persons (California State Department of Finance 2000).

A second BBS route (“‘Cottonwood’’) runs from the park’s south entrance to
approximately its center. Relatively few ravens have been observed on this route
(range 0—7) despite its having been surveyed in 20 different years, and in contrast
to the “Joshua Tree’? route, the small numbers have decreased since the early
1990’s (Fig. 2). On the “Cholla Garden” route, which runs roughly east-west in
the central portion of the park, the number of ravens observed has ranged from
seven in 1996 to 21 in 1995; no increase has been detected.

BBS surveys occur strictly along paved roads, and because ravens tend to be
attracted to roads (Knight and Kawashima 1993, Boarman and Heinrich 1999),
BBS routes potentially overestimate the abundance of ravens in an area. Further-
more, the results of surveys like the BBS that are performed only once each year
should be interpreted conservatively. Despite these caveats, increases in the num-
bers of ravens in the 1990’s on the “Joshua Tree”’ route well above numbers from
the 1970’s and 1980’s likely reflect actual increases in raven density in this area.

Like the BBS, the Adopt-a-Raven Transects were vehicular surveys. Counts
were made at roughly 0.8 km intervals on five different routes in JTNP and one
adjacent to it, ranging from twice to 35 times each. The route lengths are shorter
than for the BBS surveys (ranging between 6.4 and 20.1 km), but cover both

06 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

paved and unpaved roads. Most were repeated several times each year (Table 5).
Because observers occasionally deviated from the established protocol and varied
the distance between count locations, we calculated the average number of ravens
per stop rather than the average number per kilometer. Of the three routes sur-
veyed more than three times each, the two routes in the northeastern portion of
JTNP resulted in more raven observations per point surveyed than did the route
adjacent to the EML site. These differences could reflect a positive correlation
between raven densities and human density. They may instead, or additionally,
reflect a lower number of ravens in the Colorado Desert portion of JTNP due to
habitat preferences.

The results of a relatively recent survey of undeveloped areas of the park
supports the idea that raven densities in roadless regions in JTNP are much lower
than in areas containing roads. Camp et al. (1993) surveyed for ravens in unpo-
pulated areas adjacent to the proposed EML. Thirty-two transects totaling 283 km
were walked in a 4-week period in 1992 in a largely roadless area. For each
transect, the number of ravens observed per kilometer was calculated, and then
averaged to obtain the number of ravens per 100 km. Only eight ravens were
observed on the 32 transects surveyed. All observations were of single birds. The
density was estimated to be 4.6 per 100 km (SD = 9.78), much lower than the
mean of 36.5 ravens per 100 km estimated by Knight and Kawashima (1993)
along paved highways in the Mojave Desert.

National Audubon Society Christmas Bird Count (CBC) data have been col-
lected at Joshua Tree National Park once each winter since 1969 and at a second
site immediately west of JT[NP (Morongo Valley) since 1981. We interpreted these
data cautiously because CBC methods are not well standardized compared to other
sources of information (Bock and Root 1981). A CBC involves a group of ob-
servers counting the number of individuals of all species within a 24-km diameter
circle in a 24-hour period, although little time is spent surveying in non-daylight
hours. The participants typically divide themselves into small groups and each
group covers different, non-overlapping locations in the 24-km area. A master list
is compiled on which each group reports the total number of each species ob-
served. We calculated the number of ravens observed per party-hour (the number
ravens divided by the number of “‘party-hours’’) in an effort to partially reduce
variation in CBC data resulting from the fact that the numbers of observers par-
ticipating in the counts tends to vary among years. There was no way that we
could control for differences in amount of time spent surveying different areas
within the count circle, or for variation in weather. The number of ravens per
party hour for both the Joshua Tree National Monument CBC and the Morongo
Valley CBC showed statistically significant increases over their respective 30-year
and 18-year histories (Fig. 3, Fig. 4; Joshua Tree: r, = 0.705, p < 0.0005; Mo-
rongo Valley: r, = 0.834, p < 0.0005).

We also analyzed unpublished observations of ravens by Michael A. Patten, a
locally-based professional biologist with expertise in ornithology. Patten recorded
birds between 1987 and 1999 at five areas near JTNP: Morongo Valley, Twen-
tynine Palms, Iron Mountain (approximately 12.9 km northeast of the northeast
border of the park), Cactus City (12.9 km west of the park’s south entrance), and
Desert Center (Fig. 1). Each year, surveys were made in spring and fall of some
or all of the five areas. We calculated the average number of ravens observed at

o7

RAVEN ABUNDANCE AT JOSHUA TREE NATIONAL PARK

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98 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

3.00
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TLS
1438)
125
1.00

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O75
0.50
25

0.00
tore 1975 1980 1985 iggy) 1995 2000

Year

Fig. 3. Common Ravens observed on the Joshua Tree Christmas Bird Counts (r, = 0.705, p <
0.0005).

each of the five survey regions for spring and fall observations separately. A
Statistically significant increase in raven numbers was observed for fall surveys
(Spearman rank correlation, r, = 0.624, p < 0.05) but not for spring surveys
(Spearman rank correlation, r, = —0.036, p > 0.90).

A Breeding Bird Census (BBC) conducted in Morongo Valley at the Big Mo-
rongo Canyon Reserve annually between 1977 and 1995 produced ravens in only
a few years. The area was censused 8—9 times each spring to determine the
numbers of species breeding and/or otherwise utilizing the area. Ravens were
listed as a “visitor” in 1983, 1984, 1985, 1986, 1988, and 1994, indicating that
individuals were observed in the census area but were not observed breeding
When observed. The numbers of ravens that were observed were not provided.
The census area was 15.38 hectares in size and consisted of marsh, riparian wood-
land and mesquite thickets (95% of total area), and small areas of brush. The
habitat characteristics may have influenced the infrequency of observations since
ravens tend not to utilize woodland and thicket habitat in deserts of southern
California.

Conclusions

None of the data sets we obtained was a comprehensive assessment of Common
Raven distribution or density in JTNP for any time period. Furthermore, the ma-
jority of the sources consisted of data that were collected without the use of a
standardized methodology, and/or were collected over a short time period. Despite

RAVEN ABUNDANCE AT JOSHUA TREE NATIONAL PARK we)

2.00
1.75

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1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000

Year of Survey

Fig. 4. Common Ravens observed on the Morongo Valley Christmas Bird Counts (r, = 0.834, p
< 0.0005).

these limitations, we gained enough historical and temporal information about
ravens to reach the following qualitative conclusions:

I. Ravens were present in the southern California desert (east Mojave)
thousands of years ago.

Fossil evidence shows that ravens occupied the east Mojave Desert tens of
thousands of years ago. Observations of live individuals in the Mojave and Col-
orado Deserts date back as far as the late 1800s and early 1900s. These data
support the contention that Common Ravens are a native component of the avi-
fauna in southern California deserts.

2. Ravens have been documented in JTNP for more than 50 years.

The first documented observation of ravens in JTNP was in 1935 (Carter 1937),
later supplemented extensively by observations from Charles Adams in the mid-
1950s. Breeding in the region was suggested by observations during the Death
Valley Expedition of 1891 (Fisher 1893). Breeding Bird Atlas (BBA) data con-
firmed that ravens continue to breed in JTNP. In limited surveys in 1999, we
located eight nests in the park (Boarman and Coe 2000a).

3. Raven densities may be higher in the Mojave Desert than the Colorado
Desert.

JTNP consists of two types of desert: Mojave and Colorado. During the Adopt-
a-Raven Transects surveys, more ravens were observed along routes in the north-

100 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

ern portions of the park (Mojave) than in the central and southeast portions (Col-
orado). These observations are in agreement with those of Knowles et al. (1989)
and FaunaWest Wildlife Consultants (1991) that indicated ravens were more com-
mon in the Mojave than in the Colorado Desert based on vehicle transect surveys.
Patten et al. (in press) also reports Common Ravens as being uncommon in the
Salton Sink portion of the Colorado Desert and fewer in number than in the
Mojave Desert.

4. The numbers of ravens observed in JTNP has increased over the last 50
years.

The absence of Common Raven from Miller’s 1945 bird list for JTINP, com-
pared to the regular observations by Charles Adams in the mid-1950s may suggest
a period when populations began visibly expanding. BBS data suggest that raven
numbers have increased on the “‘Joshua Tree’’ route. Although the “‘Cottonwood”’
BBS route has not shown a corresponding increase, this route covers Colorado
Desert habitat where ravens may be less abundant (see Conclusion 3, above).

CBC data also indicate an increase in raven numbers. The number of ravens
per party hour for both the Joshua Tree National Monument CBC and the Mo-
rongo Valley CBC increased over their respective histories. Increases in ravens
in JTNP are consistent with the results of an analysis of BBS data for the Sonoran
and Mojave Deserts by Boarman and Berry (1995) showing that raven populations
increased 450—1000% over a recent 24-year period.

5. The distribution of ravens in JTNP has expanded in the last 5O years.

Common Ravens are now known to occur in locations where Charles Adams
never reported them in the mid-1950s (e.g., Cottonwood Springs and Queen Val-
ley).

6. Raven densities are lower in regions without roads.

Surveys by Camp et al. (1993) in unpopulated areas adjacent to the proposed
Eagle Mountain Landfill resulted in a density estimate of 4.63 per 100 km which
was lower than the mean of 36.5 ravens per 100 km estimated by Knight and
Kawashima (1993) along paved highways in the Mojave Desert.

7. Landfills in the Mojave Desert are some of the largest concentration areas
for ravens.

This observation was made by Knowles et al. (1989) and FaunaWest Wildlife
Consultants (1991) who surveyed landfills, sewage ponds and roads. In addition,
multi-year surveys in the western Mojave Desert at Fort Irwin (approximately
130 km north of the park), and in and around Edwards Air Force Base (approx-
imately 130 km north-east of the Park), yielded significantly more ravens at land-
fills than at sewage ponds, golf courses, city streets, and undeveloped desert lo-
cations (Boarman et al. 1995).

Observations of ravens in Joshua Tree National Park have increased and their
populations are presumably expanding. Because of their use of landfills for food,
raven numbers in JTNP will likely increase following implementation of Eagle
Mountain Landfill. A program to monitor raven populations in and around JTNP
should be implemented to evaluate expected changes and should cover areas

RAVEN ABUNDANCE AT JOSHUA TREE NATIONAL PARK 101

where ravens have occurred regularly over the past 50 years, as well as where
they have rarely occurred. Road-based surveys coupled with point counts at spe-
cific attraction sites, following standardized protocols and occurring throughout
the year, would provide the most reliable results. Following radio- and wing-
tagged ravens from the landfill would yield important data on the direct influence
the landfill has on the JTNP raven population.

Acknowledgements

We would like to thank the numerous persons who provided data and infor-
mation for this manuscript, including William Truesdell, Ray Panici, Michael A.
Patten, Chet McGaugh, Richard Camp, and JTNP staff Gillian Bowser and Joseph
Zarki. Several museums provided information from their collections including
California Academy of Sciences (Douglas Long), Los Angeles County Museum
of Natural History (Kimball Garrett), San Bernardino County Museum (Robert
McKernan), San Diego Natural History Museum (Philip Unitt), Museum of Ver-
tebrate Zoology, and Western Foundation of Vertebrate Zoology (Rene Corado).
Comments and suggestions were provided by Michael A. Patten, Richard Camp,
and Chet McGaugh. We also thank Gillian Bowser, Hank McCutchen, and Ernie
Quintana for their support of the project from its inception.

Literature Cited

Avery, M.L., M.A. Pavelka, D.L. Bergman, D.G. Decker, C.E. Knittle, G.M. Linz. 1995. Aversive
conditioning to reduce raven predation on California Least Tern eggs. Colonial waterbirds,
18(2):131-145.

Boarman, W.I. 1993. When a native predator becomes a pest: a case study. Pp. 191—206 in Conser-
vation and resource management. (S. K. Majumdar, E. W. Miller, D. E. Baker, E. K. Brown, J.
R. Pratt, and R. EK Schmalz, eds.), Penn. Acad. of Sc., Philadelphia. 444 pp.

Boarman, W.I., and S.J. Coe. 2000a. Evaluation of the distribution and abundance of Common Ravens
in and around Joshua Tree National Park. Joshua Tree National Park Resources Management
Division, Twentynine Palms, California.

Boarman, W.I., and S.J. Coe 2000b. Finding value in pre-existing data sets. Conservation biology in
practice, 1(1):32—34.

Boarman, W.I., and K.H. Berry. 1995. Common Ravens in the southwestern U.S. 1968-1972. Pp 73-—
75 in Our living resources: a report to the nation on the distribution, abundance, and health of
U.S. plants, animals, and ecosystems. (E.T. LaRoe, G.S. Farris, C.E. Puckett, PD. Doran, and
M.J. Mac, eds.), U.S. Department of Interior, National Biological Service, Washington, DC.
530 pp.

Boarman, W.I., R.J. Camp, M. Hagan, and W. Deal. 1995. Raven abundance at anthropogenic resources
in the Western Mojave Desert, California. Prepared for Edwards Airforce Base, California.
Prepared by National Biological Survey. Contact author at U.S. Geologic Survey, Western
Ecological Research Center, 5745 Kearny Villa Road, Suite M, San Diego, California, 92123.

Boarman, W.I., and B. Heinrich. 1999. The Common Raven (Corvus corax). No. 476. in The birds
of North America (A. Poole and FE Gill, eds), Philadelphia Academy of Sciences and American
Ornithologists’ Union.

Bock, C.E., and T.L. Root. 1981. The Christmas Bird Count and avian ecology. Studies in avian
biology No. 6:17—23.

Bureau of Land Management. 1990. Draft raven management plan for the California Desert Conser-
vation Area. U.S. Dept. Int., Bureau of Land Management, California Desert District, Riverside,
California.

California State Department of Finance. 2000. Historical census population of places, towns, and cities
in California, 1850-1990. Demographic Research Unit. Sacramento, California. (www.dof.ca.
gov/html/demograp/repndat.htm) August 2001.

102 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

Camp, R.J., R.L. Knight, and J. Freilich. 1993. Common Raven populations in Joshua Tree National
Monument, California. Western Birds, 24:198—199.

Carter, E 1937. Bird life at Twentynine Palms. Condor, 39:210—219.

FaunaWest Wildlife Consultants. 1991. Relative abundance and distribution of the Common Raven in
the deserts of southern California and Nevada during spring and summer of 1989. Prepared for
Bureau of Land Management, California Desert District, Contract No. YA651-CT9-340035.
Prepared by FaunaWest Wildlife Consultants, PO. Box 113, Boulder, Montana, 59632.

Fisher, A.K. 1893. The Death Valley Expedition: a biological survey of parts of California, Nevada,
Arizona, and Utah. North America Fauna no. 7.

Gilman, M.F 1935. Notes on birds in Death Valley. Condor, 37:238—242.

Grinnell, J., and A.H. Miller. 1944. The distribution of the birds of California. Pacific Coast Avifauna
no. 27.

Jefferson, G.T. 1991. A catalogue of Late Quaternary vertebrates from California: Part One, Nonmarine
lower vertebrates and avian taxa. Natural History Museum of Los Angeles County Technical
Report no 5.

Knight, R.L., and J.Y. Kawashima. 1993. Responses of raven and red-tailed hawk populations to linear
right-of-ways. J. Wildl. Manage., 57:266—271.

Knowles, C., R. Gumtow; P. Knowles, and P. Houghton. 1989. Relative abundance and distribution of
the Common Raven in the deserts of southern California and Nevada during fall and winter of
1988-1989. Prepared for Bureau of Land Management, California Desert District. Contract No.
CA950-CT8-56. Available from FaunaWest Wildlife Consultants, PO. Box 113, Boulder, Mon-
tana, 59632.

Lamb, C. 1912. Birds of a Mohave Desert oasis. Condor, 14:32—40.

Miller, A.H., and R.C. Stebbins. 1964. The lives of desert animals in Joshua Tree National Monument.
Univ. of California Press. 452 pp.

Patten, M.A., P. Unitt, and G. McCaskie. In press. Birds of the Salton Sea: status, ecology, and
biogeography. Univ. of California Press.

RECON (Regional Environmental Consultants). 1994. Annual summary report for the Eagle Mountain
Landfill Biological Mitigation and Monitoring Program, Riverside County, California. Prepared
for Mine Reclamation Corporation.

U.S. Fish and Wildlife Service. 1994. Desert tortoise (Mojave population) Recovery Plan. U.S. Fish
and Wildlife Service, Portland, OR.

van Rossem, A. 1911. Winter birds of the Salton Sea region. Condor, 13:129—137.

Accepted for publication 16 March 2001.

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CONTENTS

Structure and Standing Stock of the Fish Assemblages of San Diego Bay,
California from 1994 to 1999. Larry G. Allen, Amy M. Findlay, and
Carol IM Phhaleta..etes i aks fae ow Ae a ee Tee 49

An evaluation of the distribution and abundance of Common Ravens at
Joshua Tree National Park. William I. Boarman and Sharon J. Coe __ 86

COVER: Species Compostion for North San Diego Bay. See L.G. Allen et al., figure 6.

E QUI
SO
1017
Supp

SOUTHERN

Volume 101

ISSN 0038-3872

CALIFORNIA; ACADEMY “OF SClENCES

Supplement to Number 2

ABSTRACTS OF PAPERS

NCO 490!
RPORATED
O ‘2

S ANGEL

2002 Annual Meeting
Claremont McKenna College
Claremont, California

June 7—8, 2002

[CALIFORNIA
| ACADEMY OF SCIENCES

AUG 142002 |
| LIBRARY |

errs

BCAS-A101(2, supplement 1—48) (2002)

AUGUST 2002

D

Bulletin of the Southern California Academy of Sciences

Supplement to Volume 101, number 2

August 2002

Abstracts of Papers presented at
the Annual Meeting of the Academy
Claremont McKenna College
Claremont, California
June 7—8, 2002

SCAS 2002 Annual Meeting Committee

Dr. Ralph Appy
Dr. Jonathan Baskin
Dr. Kathryn Dickson

Dr. Daniel Guthrie

Acknowlegements

The Southern California Academy of Sciences wishes to acknowlege the following
organizations and people for their support of the 2002 Annual Meeting

Dr. Robert Phelan, U.C. Irvine
The Port of Los Angeles
Sea Grant Program, University of Southern California

STUDENT AWARD WINNERS AT 2002 ANNUAL MEETING

At the 2002 Annual Meeting, held June 7—8 at Claremont McKenna College, Claremont,
California, the following student papers and posters won awards.

Awarded by the American Institute of Fishery Research Biologists

Best Paper
Daniel Cartamil and C. Lowe. California State University, Long Beach
DIEL MOVEMENT PATTERNS OF THE OCEAN SUNFISH, MOLA
MOLA: A PRELIMINARY REPORT

1st Runner Up
Yannis P. Papastamatiou and Christopher G. Lowe, California State University Long Beach

IN SITU MONITORING OF GASTRIC pH CHANGES ASSOCIATED
WITH FEEDING IN LEOPARD SHARKS

2nd Runner up
Matthew T. Craig, P. A. Hastings, and P. K. Dayton. Scripps Institution of Oceanography

THE NEARSHORE FISH ASSEMBLAGE OF THE SAN DIEGO/LA JOLLA
ECOLOGICAL RESERVE

Honorable Mention
Ronit Lavie and C. Hogue, California State University Northridge
PARASITE-MEDIATED SEXUAL SELECTION OF GREEN
SWORDTAILS, XTPHOPHORUS HELLERI

Awarded by the Southern California Academy of Sciences

Best Poster
Ronit Lavie and C. Hogue, California State University Northridge
PARASITE-MEDIATED SEXUAL SELECTION OF GREEN
SWORDTAILS, XTPHOPHORUS HELLERI

Best Paper, Physiology
R. A. Cohen and P. Fong, University of California, Los Angeles
PHYSIOLOGICAL RESPONSES TO VARIATIONS IN SALINITY AND
NUTRIENTS BY THE BLOOM-FORMING MACROALGA ENTEROMORPHA
INTESTINALIS: IMPLICATIONS FOR USE AS A BIOINDICATOR OF
FRESHWATER AND NUTRIENT INFLUX TO ESTUARINE
AND COASTAL AREAS

Best Paper, Ecology and Evolution
K.E. Drewe and M.H. Horn. California State University, Fullerton
ONTOGENETIC RESPONSES TO TERRESTRIAL DIETS IN A NEOTROPICAL
FISH: GUT MORPHOLOGY AND DIGESTIVE ENZYME ACTIVITY IN
BRYCON GUATEMALENSIS (CHARACIDAE)

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Southern California Academy of Sciences 2002 Session Schedule

Friday June 7
Location: Pickford Auditorium

Symposium: Large Scale Marine Monitoring in the Southern California Bight

10.

11.

Chair: Stephen B. Weisberg, Southern California Coastal Water
Research Project.

8:40 SEDIMENT TOXICITY IN THE SOUTHERN CALIFORNIA BIGHT: 1998
REGIONAL MONITORING. S. M. Bay*, Southern California Coastal Water Research
Project, Westminster, CA, D. Lapota, Space and Naval Warfare Systems Center, San Diego,
CA, J. Anderson, Columbia Analytical Services, Vista, CA, T. Mikel, Aquatic Bioassay and
Consulting Laboratories, Inc., Ventura, CA, J. Armstrong, Orange County Sanitation
District, Fountain Valley, CA.

9:00 IDENTIFICATION OF CONTAMINATED SEDIMENTS IN THE SOUTHERN
CALIFORNIA BIGHT USING A BIOMARKER ASSAY (RGS: EPA METHOD 4425). J.
W. Anderson, J. M. Jones, D. McCoy, Columbia Analytical Services and E. Zeng, J. A.
Noblet, So. Calif. Coastal Water Research Project (SCCWRP).

9:20 THE SPATIAL DISTRIBUTION OF SEDIMENT CONTAMINATION IN THE
SOUTHERN CALIFORNIA BIGHT. J. A. Noblet and Shelly L. Moore, Southern
California Coastal Water Research Project, Westminster, CA, 92683-5218

9:40 A HISTORICAL VIEW OF MARINE SEDIMENT CONTAMINATION
SURVEYS IN SOUTHERN CALIFORNIA FROM 1977 TO 1998. R. W. Gossett, CRG
Marine Laboratories, Inc., Torrance, CA, 90501

10:00 MUSSEL MANIA; LONG-TERM CONTAMINANT TRENDS IN THE
SOUTHERN CALIFORNIA BIGHT. A. J. Mearns and T. P. O’Connor. National Oceanic
and Atmospheric Administration, Seattle, WA and Silver Springs, MD.

10:20 A REVIEW OF THE KELP BEDS OF ORANGE AND SAN DIEGO
COUNTIES AND THEIR RESPONSE TO EL NINOS AND LA NINAS FROM 1967 TO
2001. M. D. Curtis’ and W.J. North: ' MBC Applied Environmental Sciences, Costa Mesa,
CA. 92626 and * Caltech Kerchoff Marine Laboratory, Newport Beach, CA.

10:40 Break

11:00 Plenary Speaker: Walter Fitch, University of California, Irvine “Creation Science:
an Oxymoron”’

12:00 Lunch

E20 LARGE SCALE OCEANOGRAPHIC STUDIES OF THE CONTINENTAL
SHELF OF THE SOUTHERN CALIFORNIA BIGHT; THE EXAMPLE OF BIGHT 98
AND FUTURE APPROACHES. B. H. Jones, Department of Biological Sciences,
University of Southern California, Los Angeles, CA 90089-0371.

1:40 A HALF CENTURY OF PHYSICAL AND BIOLOGICAL OCEANOGRAPHY
IN THE SOUTHERN CALIFORNIA BIGHT WITH EMPHASIS ON FISH SPECIES
TEMPERATURE AND ZOOPLANKTON. P. E. Smith and H. G. Moser, Southwest
Fisheries Science Center [NOAA/NMEFS], 8604 La Jolla Shores Drive, La Jolla CA 92038.
2:00 ASSESSMENT OF DEMERSAL FISH AND INVERTEBRATE ASSEMBLAGES
ON THE SOUTHERN CALIFORNIA SHELF IN 1998. M. J. Allen', A. K. Groce’, D.
Diener’, V. Raco-Rands', Christina Thomas*, and Yvette Ralph* 'Southern California
Coastal Water Research Project, Westminster, CA 92683; *City of San Diego, Metropolitan
Wastewater Department, San Diego, CA; 7MEC Analytical Systems, Inc., Carlsbad, CA
92008; *Orange County Sanitation District, Fountain Valley, CA 92008.

2:20 PAH EXPOSURE AND DNA DAMAGE IN FLATFISH FROM SOUTHERN
CALIFORNIA BAYS AND HARBORS AND CHANNEL ISLANDS. J. S. Brown, Southern
California Coastal Water Research Project, Westminster, CA, 92683, and S.A. Steinert,
Computer Science Corporation, San Diego, CA, 92110

2:40 PORTS OF LONG BEACH AND LOS ANGELES BIOLOGICAL
MONITORING OF SAN PEDRO BAY. K. Green, MEC Analytical Systems, Inc. 2433
Impala Drive, Carlsbad, CA 92008

3:00 Break

4 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

12. 3:20 SOFT-BOTTOM BENTHIC INVERTEBRATE ASSEMBLAGES OF THE
SOUTHERN CALIFORNIA BIGHT. J. A. Ranasinghe!, D.E. Montagne’, D.B. Cadien?,
R.G. Velarde*, T. K. Mikel*, R.W. Smith’, S.B. Weisberg! and A. Dalkey® 'Southern
California Coastal Water Research Project, 7171 Fenwick Lane, Westminster, CA, 92683.
°County Sanitation District of Los Angeles County, P.O. Box 4998, Whittier, CA, 90607.
‘City of San Diego, 4918 N. Harbor Dr., Ste 101, San Diego, CA, 92106. *Aquatic
Bioassay and Consulting Laboratories, Inc., 29 North Olive Street, Ventura, CA, 93001.
°P.O. Box 1537, Ojai, CA 93024-1537. °City of Los Angeles, Environmental Monitoring
Division, 12000 Vista del Mar, Playa del Rey, CA 90293.

13: 3:40 DIVERSITY-ABUNDANCE RELATIONSHIPS IN BENTHIC HABITATS OF
THE SOUTHERN CALIFORNIA BIGHT Tim Mikel. Aquatic Bioassay and Consulting
Laboratories, Inc., 29 North Olive Street, Ventura, CA, 93001

14. 4:00 HOW IMPORTANT ARE NONINDIGENOUS SPECIES TO THE BENTHOS
OF SOUTHERN CALIFORNIA EMBAYMENTS? R. G. Velarde, City of San Diego,
4918 N. Harbor Dr., Ste 101, San Diego, CA, 92106, J.A. Ranasinghe, Southern
California Coastal Water Research Project, 7171 Fenwick Lane, Westminster, CA, 92683
and D.B. Cadien, County Sanitation District of Los Angeles County, P.O. Box 4998,
Whittier, CA, 90607.

15. 4:20 MARINE: THE MULTI-AGENCY ROCKY INTERTIDAL NETWORK. M. E.
Dunaway, Minerals Management Service, Camarillo 93010.

16. 4:40 POST-RESTORATION LONG-TERM MONITORING FOR THE
BATIQUITOS LAGOON ENHANCEMENT PROJECT. K. Merkel!', H. D. Henderson!, R.
A. Woodfield', and M. Carpenter? 'Merkel & Associates, Inc., San Diego, CA 92123.
*KTU+A, San Diego, CA 92103

Friday Fune 7

Location: Bauer Forum
Contributed Papers

Chairs: Ralph Appy, Port of Los Angeles, Judith Lemus, Sea Grant Program,
U.S.C., and John Dorsey, City of Los Angeles.

WZ 8:40 ATMOSPHERIC DEPOSITION OF TRACE METALS TO SANTA MONICA
BAY. K. Schiff, L. Tiefenthaler, Southern California Coastal Water Research Project, West-
minster, CA, and K. Stolzenbach, R. Lu, R. Turco, S. Friedlander, University of California
Los Angeles, Los Angeles, CA.

18. 9:00 CHARACTERISTICS, FORMATION MECHANISMS AND CHEMICAL COM-
POSITION OF ULTRAFINE PARTICLES IN VARIOUS LOCATIONS OF THE LOS AN-
GELES BASIN. Constantinos Sioutas, Si Shen, Michael D. Geller, Chandan Misra and
Seongheon Kim, University of Southern California, Department of Civil and Environmental
Engineering, 3620 South Vermont Avenue, Los Angeles, CA 90089

19. 9:20 AUTOTOMY: NOVEL PROTECTION FROM MERCURY TOXICITY IN
AQUATIC OLIGOCHAETE WORMS. Doris Vidal. Southern California Coastal Water Re-
search Project. Toxicology Department. Westminster CA 92683-5218

20. 9:40 EQUAL LOADS OF NUTRIENTS ADMINISTERED TO MACROALGAE
VIA PULSES OF DIFFERENG FREQUENCY AND MAGNITUDE AFFECT GROWTH
AND TISSUE NUTRIENTS OF ENTEROMORPHA INTESTINALIS AND ULVA EX-
PANSA. Krista Kamer', Rachel L. Kennison’, and Peggy Fong” 'Southern California
Coastal Water Research Project, Westminster CA 92683. ?University of California, Los
Angeles, Department of Organismic Biology, Ecology and Evolution, Los Angeles CA
90095.

zie 10:00 MORPHOLOGICAL VARIATION AND PATTERNS OF REPRODUCTION
AND RECRUITMENT IN LOWER INTERTIDAL POPULATIONS OF THE KELP
EGREGIA MENZIESIHT (TURNER) ARESCHOUG. Henkel, Sarah K. and Murray, Steven
N. Department of Biological Science, California State University, Fullerton, PO Box 6850,
Fullerton, CA 92834-6850

PROGRAM 5

22

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10:20 HABITAT ASSOCIATIONS OF STEELHEAD TROUT IN A SMALL STREAM
NEAR THE SOUTHERN EXTENT OF THEIR RANGE. A. P. Spina. National Marine
Fisheries Service, Southwest Region, Long Beach, CA 90802.

10:40 Break

11:00 Plenary Speaker: Walter Fitch, University of California, Irvine “Creation Science: an
Oxymoron’”’

12:00 Lunch

1:20 IN SITU MONITORING OF GASTRIC pH CHANGES ASSOCIATED WITH
FEEDING IN LEOPARD SHARKS. Yannis P. Papastamatiou and Christopher G. Lowe,
Department of Biological Sciences, California State University Long Beach, 1250 Bellflow-
er Blvd., Long Beach CA 90840.

1:40 ONTOGENETIC RESPONSES TO TERRESTRIAL DIETS IN A NEOTROPI-
CAL FISH: GUT MORPHOLOGY AND DIGESTIVE ENZYME ACTIVITY IN BRYCON
GUATEMALENSIS (CHARACIDAE). K.E. Drewe and M.H. Horn. California State Uni-
versity, Fullerton, Department of Biology, Fullerton, CA 92834

2:00 DIEL MOVEMENT PATTERNS OF THE OCEAN SUNFISH, MOLA MOLA:
A PRELIMINARY REPORT. D. Cartamil and C. Lowe. California State University, Long
Beach, Department of Biological Sciences, Long Beach, California, 90840.

2:20 INCIDENCE OF SALMONELLA IN FREE RANGING IGUANID LIZARDS
OF SOUTHERN CALIFORNIA. Jeffery Burkhart, Ron Fauntleroy, and Kelly Spencer, De-
partment of Biology, University of La Verne, La Verne, CA. 91750

2:40 OIL IMPACT ON GROWTH OF SALICORNIA VIRGINIA UNDER CON-
TROLLED TIDAL CONDITIONS. C.Y. Chen, D.D. Portugal, T. Zuniga and A.H.B.M. Wi-
jte. California State University, Long Beach, Department of Biology, Long Beach, CA,
90840.

3:00 Break

3:20 EXAMINATION OF RECRUITMENT PATTERNS IN KELP BASS, PARAL-
ABRA CLATHRATUS BY THE ANALYSIS OF MITOCHONDRIAL DNA CONTROL
REGION SEQUENCES. Christina W. Luzier and Raymond R. Wilson, Jr., California
State University, Long Beach, Department of Biological Sciences, Long Beach, CA
90840

3:40 BEHAVIORAL RESPONSES OF SCALLOPED HAMMERHEAD SHARKS,
SPHYRNA LEWINI, AND LEOPARD SHARKS, TRIAKIS SEMIFASCIATA, TO
PULSED, DIRECT CURRENT ELECTRICAL FIELDS. M.M. Marcotte. California
State University, Long Beach, Department of Biological Sciences, Long Beach, CA,
90840.

4:00 FISH SPECIES COMPOSITION FROM THE SEAFOOD MARKET OF ENSEN-
ADA, BAJA CALIFORNIA, MEXICO (2000-2001). Hernandez-Hernandez, Alejandra y Jor-
ge A. Rosales-Casian, Departamento de Ecologia, Grupo de Ecologia Pesquera Centro de
Investigaci6n Cientifica y Educacion Superior de Ensenada (CICESE) Km 107 carretera Ti-
juana-Ensenada, Ensenada Baja California, México. U.S. Mailing: P.O. Box 434844, San
Diego California 92143-4844 U.S.A.

Friday Fune 7 5-7 p.m.

Location: McKenna Auditorium

Poster Session: and Wine and Cheese Social

POLYCHAETOUS ANNELID ASSEMBLAGES ASSOCIATED WITH SEDIMENTS
NEAR SEVEN SHALLOW WASTEWATER OUTFALLS ALONG THE TIJUANA-EN-
SENADA COSTAL CORRIDOR IN NORTHERN BAJA CALIFORNIA, MEXICO. V.
Rodriguez-Villanueva', R. Martinez-Lara* and V. Macias-Zamora!:'I.1.0. Universidad
Autonoma de Baja California. Km 107 Carretera Tijuana-Ensenada. Apartado Postal
453. Ensenada, B.C. México; ?Marine Biology Laboratory, City of San Diego Ocean
Monitoring Program. 4918 North Harbor Drive, Suite # 101, San Diego, CA 92106.
U.S.A.

33.

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38.

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42.

43.

100.

44,

SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

POPULATION SYSTEMATICS OF THE CAROLINA ANOLE, ANOLIS CAROLINEN-
STS VOIGT (SQUAMATA: IGUANIA: POLYCHROTIDAE): GEOGRAPHIC VARIA-
TION IN MORPHOLOGY. W.C.H. Chun! and J.W. Archie” 'University of California,
Department of Organismic Biology, Ecology, and Evolution, Los Angeles, CA, 90095;
and ’California State University, Department of Biological Sciences, Long Beach, CA,
90840.

SALT TOLERANCE AND REMEDIATION POTENTIAL OF SALIX LASIOLEPIS: A
NATIVE CALIFORNIA WILLOW. A. Ferrus-Garcia, C.M Vadheim, J. Roberts. Depart-
ment of Biology, CSU Dominguez Hills, Carson CA 90747

NORTHERN ORANGE COUNTY FALL 2001 WEATHER SUMMARY G.P. Hannes, Cal-
ifornia State University, Fullerton, Department of Geogrpahy, Fullerton, CA 92634.
TROPHIC LEVELS AND HEAVY METAL CONCENTRATIONS OF TERNS AT TWO
CALIFORNIA NESTING COLONIES. M.H. Horn', A.Z. Mason’, D.R. Smith', E.A. Lo-
gothetis* and C.T. Collins” 'Department of Biological Science, California State University,
Fullerton, Fullerton, CA 92834 *Department of Biological Science, California State Univer-
sity, Long Beach, Long Beach, CA 90840, 31810 Perry Avenue, Wilmington, NC 28403.
ACANTHOCHONDRIA SP. A, A NEW SPECIES OF PARASITIC COPEPOD POECI-
LOSTOMATOIDA: CHONDRACANTHIDAE) ON THE CALIFORNIA HALIBUT, PAR-
ALICHTHYS CALIFORNICUS, FROM SANTA MONICA BAY, CALIFORNIA. Julianne
Kalman. Department of Organismic Biology, Ecology, and Evolution, University of Califor-
nia, Los Angeles (UCLA), Los Angeles, CA 90095-1606

PARASITE-MEDIATED SEXUAL SELECTION OF GREEN SWORDTAILS, X7PHO-
PHORUS HELLERT R. Lavie and C. Hogue, California State University, Northridge, De-
partment of Biology, Northridge, CA, 91330

THE BENTHIC COMMUNITY OF SAN DIEGO BAY. E.C. Nestler, D. Pasko, and T. D.
Stebbins. Marine Biology Laboratory, City of San Diego Ocean Monitoring Program, 4918
N. Harbor Drive, Suite #101, San Diego, CA 92106, USA.

PROBABLE LATERITE IN THE PALEOCENE LAS VIRGENES SANDSTONE, SOL-
STICE CANYON, SANTA MONICA MOUNTAINS, CALIFORNIA. G.R.Noriega, H.O.
Hernandez, Dr. P. Ramirez, California State University Los Angeles, Department of Geolog-
ical Sciences, Los Angeles, CA, 90032

ASSESSMENT OF THE HEALTH OF KELP HABITATS ALONG THE NORTH COAST
OF SANTA MONICA BAY. B. Reed!, P. Fong’, and J.R. Smith? ‘Santa Monica BayKeeper,
*University of California, Los Angeles (Funded by the Santa Monica Bay Restoration Foun-
dation).

SOIL MICROBIAL ACTIVITY AND MYCORRHIZAL ASSOCIATION IN A SOUTH-
ERN CALIFORNIAN SALT MARSH. Matthew W. Vandersande and Dr. Richard KF Am-
brose Environmental Science and Engineering Program, UCLA

OCCURRENCE OF Gyrodactylus perforatus (MONOGENEA) ON ITS FISH HOST Cleve-
landia ios (Gobiidae) FROM BODEGA BAY AND TOMALES BAY, CALIFORNIA. M. P.
Walberg, E. Diamant, and K. Wong. University of California, Los Angeles, Department of
Organismic Biology, Ecology, and Evolution, Los Angeles, CA, 90095.

A COMPARISON OF THE VOCALIZATIONS OF TWO SPECIES OF FYLING FOXES
IN THE SAMOAN ARCHIPELAGO. Eiler, K; J. Newmark; B. Drummond; C. Stewart;
and S. Banack, California State University, Department of Biological Science, Fullerton,
CA. 92831.

Saturday fune 8

Location: Bauer Forum

Symposium: Conservation Management

Chair: Brad Blood, Sapphos Environmental.

9:00 MANAGEMENT OF THE CALIFORNIA LEAST TERN BREEDING POPULA-
TION. Kathy Keane, Keane Biological Consulting, 5546 Parkcrest Street, Long Beach CA
90808 USA, keanebio@cs.com

PROGRAM

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9:20 CONSERVATION OF THE ENDANGERED SOUTHERN CALIFORNIA
STEELHEAD IN THE VENTURA RIVER: AN UPDATE ON THE PROPOSED REMOV-
AL OF MATILIJA DAM. Sabrina L. Drill. University of California Cooperative Extension,
2 Coral Circle, Monterey Park, CA 91755.

9:40 CONSERVATION DILEMMAS INVOLVING ENDANGERED SPECIES IN
THREE SOUTHERN CALIFORNIA HABITATS; SAN MIGUEL ISLAND, BOLSA CHI-
CA WETLANDS AND RIPARIAN WOODLANDS. Daniel A. Guthrie, Claremont Mc-
Kenna College, Claremont, Ca. 91711

10:00 THE IMPORTANCE OF MANAGEMENT OF THE NATIVE PARASITIC
PLANT CUSCUTA SALINA IN SOUTHERN CALIFORNIA SALT MARSH HABITAT.
Christina Simokat, Department of Biology, California State University San Marcos, San
Marcos, CA 92096.

10:20 AVIAN POPULATIONS IN DIMINISHING OPEN SPACE: A SURVEY OF
THE BIRDS OF SIGNAL HILL, CA. V. Anne Short, Department of Biological Sciences,
California State University, Long Beach, California.

10:40 Break

11:00 Plenary Speaker: Gregor Hodgson, U.C.L.A. on “John Q, Public Saves Coral
Reefs.”’ Pickford Auditorium

12:00 Lunch

Symposium: Exotic Species

Chair: Dan Guthrie, Claremont Colleges

1:40 ARE SOUTHERN CALIFORNIA’S CHANGING COASTAL WATERS AND
NEARSHORE BIOLOGICAL COMMUNITIES BECOMING MORE SUSCEPTIBLE TO
INVASION BY EXOTIC SEAWEEDS? S. N. Murray. Department of Biological Science,
California State University, Fullerton, CA 92834-6850

2:00 WHAT IS NONINDIGENOUS AND IS IT ALL BAD? J. N. Baskin and T. R.
Haglund, California State Polytechnic University Pomona, Biological Sciences Department,
Pomona, CA 91768.

2:20 THE MARINE INVADERS OF CALIFORNIA: LESSONS FROM SAN FRAN-
CISCO AND SAN DIEGO. Jeffrey A. Crooks. Tijuana River National Estuarine Research
Reserve, Imperial Beach, CA. 91933

2:40 U.S. RESPONSE TO POTENTIAL ECOLOGICAL THREAT TO SOUTHERN
CALIFORNIA ECOSYSTEMS BY THE INTRODUCED MARINE CHLOROPHYTE
CAULERPA TAXIFOLIA. R.A. Woodfield and K.W. Merkel, Merkel & Associates, Inc.,
5434 Ruffin Rd., San Diego, CA, 92123

3:00 Break

3220 EXOTIC AQUATIC TURTLES ON THE WEST COAST: CONSIDERATIONS
AND IMPLICATIONS. Mark R. Jennings (1), Dan C. Holland (2) and Robert H. Good-
man, Jr. (3). (1) Rana Resources, 39913 Sharon Avenue, Davis, CA 95616 (2) 334A East
Fallbrook Street, Fallbrook, CA 92028 (3) Citrus Community College, 1000 W. Foothill
Blvd., Glendora, CA 91741

3:40 EXOTIC FISH SPECIES AND THEIR IMPACTS ON SMALL COASTAL LA-
GOONS IN SOUTHERN CALIFORNIA. Camm C. Swift! and Dan C. Holland’. Emeritus,
Section of Fishes, Natural History Museum of Los Angeles County, Los Angeles, CA
91007; and 334A East Falbrook, Fallbrook, CA 92028

4:00 INVADER IN THE OPEN SEA! THE NEW ZEALAND MARINE SNAIL PHI-
LINE AURIFORMIS IN SOUTHERN CALIFORNIA COASTAL WATERS. D. B. Ca-
dien, Marine Biology Lab, County Sanitation Districts of Los Angeles County, 24501 S.
Figueroa St., Carson, CA, 90745

4:20 INTERACTION BETWEEN NATIVE FISH, HABITAT, AND EXOTIC FISH
SPECIES IN THE MIDDLE SANTA ANA RIVER, SOUTHERN CALIFORNIA. Camm C.
Swift, Emeritus, Section of Fishes, Natural History Museum of Los Angeles County, Mail-
ing address: 346 West Le Roy Avenue, Arcadia, CA 91007

SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

Saturday June 8
Location: Pickford Auditorium

Symposium: Rocky Reef Monitoring

Chair: Dan Pondella, Vantuna Research Group, Occidental College and Robert

D7.

58.

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60.

61.

62.

63.

64.

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Grove, Southern California Edison.

8:45 WELCOME AND INTRODUCTION. D Pondella and R. Grove

9:00 MONITORING OF NEARSHORE MARINE HABITATS FOLLOWING
BEACH REPLENISHMENT ACTIVITIES. L. Honma! and R. Rundle* 'AMEC Earth &
Environmental, 5510 Morehouse Dr., San Diego, CA 92121. ? San Diego Association of
Governments, 401 B Street Suite 800, San Diego, CA 92101.

9:20 ANALYSIS OF AERIAL PHOTOGRAPHS TO DETERMINE THE EFFECTS
OF THE DIABLO CANYON POWER PLANT THERMAL DISCHARGE ON KELP
CANOPIES. Scott Kimura and James Strampe (TENERA Environmental, San Luis Obispo,
CA 93401)

9:40 INTERPRETING HISTORICAL RECORDS OF SIZES OF KELP BEDS (PART
1). W. J. North., W.M. Keck Engineering Laboratories, California Institute of Technology,
Pasadena, CA, 91125

10:00 INTERPRETING HISTORICAL RECORDS OF SIZES OF KELP BEDS (PART
2). W. J. North., W.M. Keck Engineering Laboratories, California Institute of Technology,
Pasadena, CA, 91125

10:20 UPDATE ON THE SAN CLEMENTE ARTIFICIAL REEF PROGRAM. R.
Grove, Southern California Edison; S. Schroeter, UCSB.

10:40 Break

11:00 Plenary Speaker: Gregor Hodgson, U.C.L.A. on “John Q, Public Saves Coral
Reefs.”’ Pickford Auditorium

12:00 LUNCH

1:20 REEF—A VOLUNTEER FISH MONITORING PROGRAM IN CALIFORNIA.
C.V. Pattengill-Semmens. Reef Environmental Education Foundation, P.O. Box 246, Key
Largo, FL 33037, 206-529-1240, christy @reef.org

1:40 LONG-TERM CHANGES IN FISH POPULATIONS IN THE VICINITY OF
DIABLO CANYON POWER PLANT, CENTRAL CALIFORNIA. J.C. Carroll and J.R.
Steinbeck. Tenera Environmental, 225 Prado Rd., Suite D, San Luis Obispo, CA, 93401.
2:00 DECLINES IN ROCKY REEF FISH POPULATIONS: HAVE DIFFERENT SPE-
CIES RESPONDED SIMILARLY TO ENVIRONMENTAL CHANGE? A. Brooks, R.
Schmitt, & S. Holbrook. Marine Science Institute, University of California Santa Barbara,
Santa Barbara, California, 93106 USA

22.0 LONGTERM DECLINE OF ICHTHYOPLANKTON ABUNDANCE IN SANTA
MONICA BAY. D.J. Pondella, II. Vantuna Research Group, Occidental College, Depart-
ment of Biology, Los Angeles, CA, 90041.

2:40 REGIME SHIFTS IN CALIFORNIA CURRENT ZOOPLANKTON ASSEM-
BLAGES. M.D. Ohman! and B.E. Lavaniegos' 'Integrative Oceanography Division,
Scripps Institution of Oceanography, La Jolla, CA 92093-0218, and *CICESE, Ensenada,
Mexico

3:00 BREAK

3:20 MONITORING SUBTIDAL COMMUNITY CHANGES AT SURVEY ROCK,
ANACAPA ISLAND: FORTY YEARS AND STILL COUNTING. J. Engle’, J. Altstatt*, R.
Ambrose’, J. Carroll+ and J.A. Coyer® |! Marine Science Institute, University of California,
Santa Barbara, CA 93106; ?Santa Barbara ChannelKeeper, 120 W. Mission St., Santa Bar-
bara, CA 93101; *Department of Environmental Engineering, University of California, Los
Angeles, CA 90024; *Tenera Environmental, San Luis Obispo, CA 93401; °Dept. of Marine
Biol. University of Groningen, The Netherlands

3:40 THE NEARSHORE FISH ASSEMBLAGE OF THE SAN DIEGO/LA JOLLA
ECOLOGICAL RESERVE. Craig, M. T., P. A. Hastings, And P. K. Dayton. Scripps Institu-
tion Of Oceanography, 9500 Gilman Dr. Mail Code 0208, La Jolla, Ca 92093-0208.

PROGRAM 9

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4:00 REMOTE TRACKING OF GIANT SEA BASS (Stereolepis gigas) USING AN
ACOUSTIC SENSORY ARRAY AROUND ANACAPA ISLAND. Michael L. Domeier.
Pfleger Institute of Environmental Research, 901-B PIER View Way, Oceanside, CA 92054
4:20 SEXUAL DICHROMATISM AND SPAWNING BEHAVIOR OF THE KELP
BASS, PARALABRAX CLATHRATUS, FROM SANTA CATALINA ISLAND, CALI-
FORNIA. B.E. Erisman. Nearshore Marine Fish Research Program, Department of Biology,
California State University, Northridge, CA, 91330-8303

4:40 REPRODUCTIVE BEHAVIOR AND MATING SYSTEM OF THE TEMPER-
ATE WRASSE, HALICHOERES SEMICINCTUS. M.S. Adreani. Nearshore Marine Fish
Research Program, Department of Biology, California State University, Northridge, CA,
91330:

Saturday June 8

Location: Bauer 35

Contributed Papers

Chair: Dr Raymond Wilson and Dr. David Huckaby, CSU Long Beach

9:00 PUTATIVE FUNCTION OF TYROSINE D OF PHOTOSYSTEM I PROBED
BY FLUORESCENCE AND OPTICAL ABSORBANCE SPECTROSCOPY. Jennifer H.
Jones and Richard J. Debus. Department of Biochemistry, University of California, River-
side, CA 92521.

920 FIELD VALIDATION OF CHRONIC SUBLETHAL DREDGED MATERIAL
LABORATORY BIOASSAYS: PROGRAM DESIGN. M.A.Irwin, D.W. Moore. MEC Ana-
lytical Systems Inc. 2433 Impala Drive Carlsbad, CA 92008. T.S. Bridges. Waterways Ex-
periment Station, U.S. Army Corps of Engineers, 3909 Halls Ferry Road, Vicksburg, MS,
39180

9:40 FLOWER DENSITY EFFECTS ON POLLINATION OF ARTICHOKE THIS-
TLE (Cynara cardunculus L. Asteraceae). L. Clarke and S. Banack, California State Univer-
sity, Fullerton, Department of Biological Sciences, Fullerton, CA 92834-6850

10:00 COPPER TOLERANCE AND REMEDIATION POTENTIAL OF SALIX LASI-
OLEPIS: A NATIVE CALIFORNIA WILLOW. CM Vadheim, K Williams, J. Roberts.
Department of Biology, CSU Dominguez Hills, Carson CA 90747.

10:20 WHAT DOES IT TAKE TO BE A HERBIVORE?—GUT STRUCTURE AND
FUNCTION IN THREE SPECIES OF NEW WORLD SILVERSIDE FISHES (TELOSTEI:
ATHERINOPSIDAE) WITH DIFFERENT DIETS. M.H. Horn, A. Gawlicka, E.A. Logothe-
tis, A.M. Jones, J.W. Cavanagh, D.P. German and C.T: Freeman. Department of Biological
Science, California State University, Fullerton, CA, 92834

10:40 Break

11:00 Plenary Speaker: Gregor Hodgson, U.C.L.A. on “John Q, Public Saves Coral
Reefs.”’ Pickford Auditorium

12:00 LUNCH

1:20 PHYLOGENY AND BIOGEOGRAPHY OF THE SERANNID FISH GENUS
EPINEPHELUS. M. T. Craig. Scripps Institution of Oceanography. 9500 Gilman Dr. Mail
Code 0208, La Jolla, CA 92093-0208.

1:40 FEEDING PREFERENCES AND ASSIMILATION EFFICIENCIES IN THE
HERBIVOROUS MARINE SNAIL LITHOPOMA UNDOSUM (TURBINIDAE). Erin Cox
and Steve Murray, 800 N. State College, California State University, Fullerton, CA, 92834-
6850

2:00 WHENCE HAVE THEY COME, THE ABYSSAL GRENADIERS? Raymond R.
Wilson, Jr. and Phoebe Attia, California State University, Long Beach, Department of Bio-
logical Sciences, Long Beach, CA 90840

2:20 PHYSIOLOGICAL RESPONSES TO VARIATIONS IN SALINITY AND NU-
TRIENTS BY THE BLOOM-FORMING MACROALGA Enteromorpha intestinalis: IMPLI-
CATIONS FOR USE AS A BIOINDICATOR OF FRESHWATER AND NUTRIENT IN-
FLUX TO ESTUARINE AND COASTAL AREAS. R. A. Cohen and P. Fong. University of
California, Department of Organismic Biology, Ecology and Evolution, Los Angeles, CA,
90095-1606.

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SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

2:40 THE USE OF AQUATIC INVERTEBRATES TO IDENTIFY ECOLOGICAL
TRENDS IN URBAN FRESHWATER STREAMS. W.H. Isham. MEC Analytical Systems,
Inc. Carlsbad, CA, 92008.

3:00 BREAK

3:20 COMPARISON OF FEEDING GUILD STRUCTURES OF INTERTIDAL FISH-
ES FROM CALIFORNIA AND CHILE: A MEASURE OF COMMUNITY CONVER-
GENCE. K. S. Boyle and M. H. Horn. Department of Biological Science, California State
University, Fullerton, Fullerton, CA 92834-6850

3:40 DIGESTIVE ENZYME ACTIVITY IN HERBIVOROUS AND CARNIVOROUS
PRICKLEBACK FISHES (Stichaeidae): ONTOGENETIC AND PHYLOGENETIC EF-
FECTS. D.P. German, M.H. Horn, and A. Gawlicka. Department of Biological Science,
California State University, Fullerton, CA 92834

4:00 INFLUENCES ON THE SELECTION OF SCIENCE AS A STUDY AND CA-
REER. Lisa Marin-Burkhart, Claremont Graduate University

SATURDAY Fune 8

Location: Burns Lecture Hall
Symposium: Research Training Program Presentations

Chair: Richard and Martha Schwartz, Torrance High School and
L.A. County Schools

8:30 Welcome and Introduction. Gloria Takahashi

8:45 ANALYSIS OF PROTEOLYTIC ACTIVITY OF THE CARNIVOROUS PLANT
NEPENTHES. Jason Bae. California State University, Fullerton, Department of Biological
Science, Fullerton, CA 92831-3599

9:00 EFFECTS OF IN-UTERO COCAINE EXPOSURE ON THE DEVELOPING
BRAIN. Amruta Kulkarny and Dr. Lynne Smith, Harbor UCLA REI 30427 Via Rivera,
Ranch Palos Verdes, CA 90275

a5 NEUROANATOMIC OBSERVATIONS OF THE BRAIN IN AUTISM: NEU-
ROIMAGING STUDIES USING THE TECHNIQUE OF COREGISTRATION. C.K. Chen.
Research and Education Institute, Harbor- UCLA Medical Center, Department of Radiology,
Torrance, CA 90502.

9:30 ON THE EFFECT OF LIGHT INTENSITY ON THE ELECTRICAL CONDUC-
TIVITY OF FILAMENTOUS FUNGI. A.G. Craig. SCJAC Research Training Program.
9:45 INTERNUCLEOSOMAL DNA CLEAVAGE DETECTED IN MK-801 IN-
DUCED RATS BUT SHOW NO SIGN OF CASPASE-3 ACTIVATION IN CELL DEATH.
R. Deniskin* and D. Fujikawa*//. *Experimental Neurology Laboratory, VA Greater Los
Angeles Healthcare System, Sepulveda Ambulatory Care Center and Nursing Home Unit,
Sepulveda, CA 91343, U.S.A.; //Department of Neurology and Brain Research Institute,
UCLA School of Medicine, Los Angeles, CA 90095, U.S.A.

10:00 URBANIZATION OF COASTAL WATERS B CONCOCTING HORMONAL
CHAOS. L.R. Patel and S.M. Bay, Southern California California Coastal Water Research
Project (SCCWRP), Westminster, CA 92683.

10:15 CORRELATION DYNAMICS IN “CIRCUIT MOLECULES” WITH CHAOTIC
LINKS. J. Manasson and V. A. Manasson. WaveBand Corporation, Los Angeles, CA, 90501.
10:30 Break

11:00 Plenary Speaker: Gregor Hodgson, U.C.L.A. on “John Q, Public Saves Coral
Reefs.”’ Pickford Auditorium

12:00 Lunch Break

1:00 INSIGHT INTO THE INTEL SCIENCE TALENT COMPETITION. Student ap-
plicants from past year.

he Bs, REPORT ON THE AJAS MEETING IN BOSTON, FEB. 2002.
Student participants from this year.
1:30 DISTRIBUTION OF OXIDATIVE AND GLYCOLYTIC ENZYMES IN ELEC-

TROCYTES OF PHYLOGENTICALL DIVERSE SPECIES OF FISH. Edward Smetak, Jr.,
La Habra High, SCJAS RTP, and Dr. Glenn Kageyama, Mentor, California State Polytech-
nic University, Pomona, Department of Biological Sciences, Pomona, CA, 91768

PROGRAM 11

90.

92.

93.

94.

95.

96.

97.

98.

1:45 THE EFFECT OF LIGHT ON THE ACCUMULATION OF THE NUCLEAR-
ENCODED psbA BINDING PROTEINS IN VASCULAR PLANTS. Monica Singh, Maya
E. Mazon, Laura Arce and Amybeth Cohen, Dept. of Biological Science, California State
University, Fullerton, CA 92834-6850

2:15 THE EFFECTS OF ENDOTHELIAL POLARITY AND ALZHEIMER’S DIS-
EASE ON MONOCYTE MIGRATION IN THE HUMAN BRAIN. Wei Liang. Alhambra
High School, Alhambra, CA, 91801; University of Southern California, Department of Bio-
chemistry and Molecular Biology, Los Angeles, CA

2:30 DNA STRUCTURE AFFECTS SODIUM BISULFITE CONVERSION OF NU-
CLEOTIDES. D.M. Chen and C.L. Hsieh. University of Southern California/Norris Cancer
Center, Department of Urology, Los Angeles, CA, 90033-0804.

2:45 THE EFFECTS OF UROKINASE-TYPE PLASMINOGEN ACTIVATOR (uPA)
INHIBITION ON CRANIAL NEURAL CREST MIGRATION. H.L. Marr and M.A.J. Sel-
leck. University of Southern California, Keck School of Medicine, Department of Cell and
Neurobiology, Los Angeles, CA, 90089.

3:00 Break

3:30 GENETICS OF DAUER LARVAE FORMATION IN CAENORHABDITIS
BRIGGSAE. P. Shirley and I. Takao, California Institute of Technology, Department of Bi-
ology, Pasadena, CA, 91125.

3:45 RETROVIRAL-MEDIATED TRANSFER AND EXPRESSION OF THE NEO-
MYCIN AND HYGROMYCIN B DRUG RESISTANCE GENES. Annie Li and Vicky
Sung, Dr. Michael Lai Research Group, University of Southern California School of Medi-
cine, Department of Molecular Biology and Immunology, Los Angeles, CA, 90033

4:00 BROCA’S AREA’S CRITICAL ROLE IN IMITATION. Jake Marcus, Crossroads
School, Santa Monica, CA, 90404, Marc Heiser, UCSE San Francisco, CA, 94143, Fumiko
Maeda, Marco Iacoboni, Ahmanson Lovelace Brain Mapping Center, Los Angeles, CA,
90095

4:15 OXIDATION OF SUBSTIUTED PHOSPHINES WITH SINGLET OXYGEN:
INTRA- VS. INTER- MOLECULAR PATHWAYS. Timothy Dong, Dr. Matthias Selke,
California State University, Los Angeles, Dept. of Chemistry, Los Angeles, CA 90032

ABSTRACTS

1 SEDIMENT TOXICITY IN THE SOUTHERN CALIFORNIA BIGHT: 1998 REGIONAL
MONITORING

S.M. Bay, Southern California Coastal Water Research Project, Westminster, CA, 92683; D.
Lapota, Space and Naval Warfare Systems Center, San Diego, CA; J. Anderson, Columbia
Analytical Services, Vista, CA; T. Mikel, Aquatic Bioassay and Consulting Laboratories, Inc.,
Ventura, CA; and J. Armstrong, Orange County Sanitation District, Fountain Valley, CA

Sediment from 303 sites on the continental shelf between Point Conception, California, and the
United States-Mexico international border was sampled in 1998 using a stratified random design.
Toxicity was evaluated using three methods: amphipod (Eohaustorius estuarius) survival, the P450
human reporter gene system (HRGS) test, and inhibition of phytoplankton (Gonyaulax polyedra)
bioluminescence (QwikSed). Amphipod toxicity was most prevalent in bay and harbor areas, where
13-39% of the area (depending upon the stratum) was toxic. The QwikSed test was the most sensitive
of the toxicity indicators. HRGS gene activity was induced by sediment extracts from 30 stations,
with most of the induction produced by samples from port/industrial or marina areas. The QwikSed
test results were not correlated with either amphipod survival or HRGS response and the correlation
between HRGS and amphipod survival was significant but low (r = 0.285). The three test responses
were combined into an integrated assessment of sediment quality. The integrated assessment identified
19% (651 km?) of the SCB as areas of potential or high concern. Areas of high concern (2.1%) were
almost exclusively located within harbors and bays, while areas of potential concern were present in
all strata tested. Temporal differences in toxicity were apparent in San Diego and offshore mid-depth
areas.

2 IDENTIFICATION OF CONTAMINATED SEDIMENTS IN THE SO. CALIF. BIGHT USING
A BIOMARKER ASSAY (RGS; EPA METHOD 4425)

J. W. Anderson, J. M. Jones, D. McCoy, Columbia Analytical Services and E. Zeng, J. Noblet,
So. Calif. Coastal Water Research Project (SCCWRP)

Samples from Bight ’98 were extracted at the SCCWRP laboratory and extracts from 267 stations
were sent to Columbia Analytical Services for testing with the human reporter gene system (HRGS),
now called EPA method 4425. Small amounts (2—20: L) of the extracts are applied to replicate culture
wells with about 1 million transgenic cells. If CYP1A-inducing compounds (PAHs, PCBs, dioxins,
furans) are present in the extract the cells produce a luminescent enzyme as a function of the concen-
trations and potencies of the compounds. The responses to the sediment extracts were reported as wg
of Benzo[a]pyrene equivalents per g dry weight. When the PAH analyses were available, total PAHs
were plotted against the 4425 data. The regions evaluated in this comparison were north, central,
south, Santa Monica Bay, San Diego, embayments, rivers, and POTWs. Correlation coefficients for
all regions, except the northern Bight, were significant (r? values from 0.63 to 0.87). Two stations on
the Palos Verdes shelf were above the curve suggesting contributions from PCBs or other inducing
compounds. There was no correlation between the measured PAHs and the 4425 responses in the
northern Bight, and the highest value observed (900 wg/g B[a]PEq) was from Coal Oil Point, an oil
seep area. These findings suggest that petroleum compounds other than those normally measured may
be CYPIA inducers. Overall, the findings from the 4425 testing provide an excellent signal for the
need for further investigation and monitoring of sites where there is the potential for chronic ecological
effects.

3 THE SPATIAL DISTRIBUTION OF SEDIMENT CONTAMINATION IN THE SOUTHERN
CALIFORNIA BIGHT

J.A. Noblet and S.L. Moore. Southern California Coastal Water Research Project, Westminster,
CA, 92683-5218

The results from the sediment chemistry analyses performed as part of the 1998 Regional Marine
Monitoring Study are presented. A total of 361 samples of surface sediments (O—2 cm) were collected;

12

ABSTRACTS 13

including 290 stations in United States waters from Point Conception to the US-Mexico border, and
71 stations from Mexican waters off of Baja California. Sampling stations were selected using a
stratified random sampling design. The individual strata selected for study included both geographic
and anthropogenic associations. Sediment samples were analyzed for TOC, TN, grain size, trace
metals, Chlordane, DDT, PAHs, and PCBs. The results show that 85% of the bight area is contaminated
by at least one organic pollutant, and 50% of the bight area sediments are enriched in at least one
trace metal. The overall result is that 88% of the bight area sediments are contaminated by at least
one anthropogenic pollutant. Although the contamination is widespread, the concentrations of most
target analytes are low relative to sediment quality guidelines over a large majority of the bight area.
Higher levels of sediment contamination are localized in proximity to past or present point sources,
and/or are related to specific anthropogenic activities.

4 A HISTORICAL VIEW OF MARINE SEDIMENT CONTAMINATION SURVEYS IN
SOUTHERN CALIFORNIA FROM 1977 TO 1998

Richard Gossett. CRG Marine Laboratories, Inc., Torrance, CA, 90501

Selected stations from the near-coastal marine sediments of Southern California were surveyed
periodically for trace contaminant levels in1977, 1985, 1990, 1994, and 1998 as part of the Southern
California Coastal Water Research Project’s Reference Surveys and the Bight Surveys. The chemical
analyses were essentially performed by the same personnel for all the surveys and offers a unique
opportunity to view the historical changes in both the contaminant trends but also in the methodology
used over this 21 year time period.

5 MUSSEL MANIA: LONGTERM CONTAMINANT TRENDS IN THE SOUTHERN CALI-
FORNIA BIGHT

A.J. Mearns and T. P. O’Connor. National Oceanic and Atmospheric Administration, Seattle,
WA and Silver Springs, MD

Twenty one of the over 260 inter-tidal NOAA National Mussel Watch stations are located in the
Southern California Bight and most are located adjacent to regional monitoring grids. Mussels have
been collected and analyzed annually or biennially since 1986. Concentrations of DDT, other organ-
ochlorine pesticides, tributyl tin, and PCB’s continued to decline throughout the Bight during the
1990’s, following major rapid decreases that occurred between 1965 and 1985. Palos Verdes is no
longer “‘the’’ hot spot with respect to DDT or PCB’s; mussels near marinas and harbors are the most
contaminated with PCB’s and chlordane. Levels of organochlorines at distant urban stations, such as
Point Dume, are now nearly equivalent to those at remote sites. Organochlorines in mussels are 100-
times less contaminated than they were in the early 1970’s, and ten times cleaner than in the early
1980’s. They also may be cleaner than at any time since World War IH. Concentrations of polycyclic
aromatic hydrocarbons (PAH’s) remain one or more orders of magnitude higher in bays and harbors
than along the coast. Fingerprinting suggests the dominant source is combustion, not oil spills. Con-
taminant concentration trends in mussels no longer are related to trends in wastewater emissions. Other
factors controlling contaminant variability include year-to-year variations in storm-water runoff, marina
flushing and episodic oceanic events. Further treatment and industrial source control of wastewater
effluents will provide no further benefit in reducing coastal contamination whereas control of surface
water runoff, atmospheric inputs and marina/vessel-related sources may.

6 A REVIEW OF THE KELP BEDS OF ORANGE AND SAN DIEGO COUNTIES AND THEIR
RESPONSE TO EL NINOS AND LA NINAS FROM 1967 TO 2001

M.D. Curtis’! and W.J. North?. 'MBC Applied Environmental Sciences, Costa Mesa, CA 92626
and *Caltech Kerchoff Marine Laboratory, Newport Beach, CA

In 1985, the San Diego Regional Water Quality Control Board (Board) stipulated in permits it
issued that kelp beds near each major discharger into the Pacific Ocean be photographed annually by
means of vertical and aerial infrared photography, to record as best possible the maximum areal extent

14 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

of any canopies present among the 24 distinct beds that occur offshore of Orange and San Diego
Counties. A consortium of dischargers was formed to develop a plan with the Board that would fulfill
the prescribed requirements. Surveys were to be conducted several times per year to determine the
maximum canopy extent for each year. As the surveyor selected, Dr. Wheeler J. North, had been
independently assessing the kelp beds using this methodology since 1967, the historical data provided
a solid foundation for the new data set.

The 34 year data set provides a synoptic view of the performance of 24 kelp beds. Although the
intention was that a synoptic survey of the beds would allow a determination of the potential detri-
mental effects of waste water (both heated effluent and sanitary) on the kelp beds, it also provided
insight as to the effects on the kelp beds from five major El Ninos and five major La Ninas that
occurred during this period. Analysis of the data indicates that the kelp beds may respond strongly to
both occurrences:

This total record can be subdivided into two periods, each exhibiting very different behavior. The
history from 1967 up through 1979 consisted of relatively small fluctuations. The remainder, from
1980 onward, was characterized by large fluctuations ranging from a minimum of 0.379 km? in 1984
to a maximum of 16.868 km? in 1989. The minimum value corresponded to the final year of a major
El] Nino while 1989 represented the first year of a large La Nina that occurred during a large stimu-
latory period unmatched by anything else in the 34 year history. This was followed by the largest (by
some factors) El Nino of the century in 1997—1998 that resulted in the loss of 98% of the kelp canopy
coverage. A large La Nifia in 1999-2000 effected a recovery to about 33% of the 1989 total.

Each of the 24 kelp beds of Orange and San Diego County were monitored during these anomalous
events by the means of color aerial infrared photographs taken on a quarterly basis. These photographs
were taken under as close to similar conditions as possible. From these photographs, the greatest areal
extent of each of the separate kelp canopies was determined for each year. Based on these data, a
synopsis of the health of each of the kelp beds and the effects of these environmental perturbations,
as it compares with the other kelp beds in the region, can be determined. Although it is not possible
to determine the cause of a decline or decrease in a single kelp bed by aerial photographs, it is
effective at showing whether the bed in question is responding to an area wide event, or if an atypical
pattern has manifested. This then becomes a very cost effective tool to determine where to focus
additional concentrated efforts on beds that may be responding atypically.

rs LARGE SCALE OCEANOGRAPHIC STUDIES OF THE CONTINENTAL SHELF OF THE
SOUTHERN CALIFORNIA BIGHT: THE EXAMPLE OF BIGHT 98 AND FUTURE AP-
PROACHES

Burton H. Jones, Department of Biological Sciences, University of Southern California, Los
Angeles, CA 90089-0371

Stormwater runoff, sewage discharge, aeolian input, and other sources contribute to the contami-
nation of our coastal waters in the Southern California Bight. The Water Quality Group of the Bight
98 project undertook the task of examining the impact of stormwater runoff during the winter 1998—
99. The study provides insights about the locations and magnitude of influence of stormwater and its
relationship to the size of rainfall events. However, this study and other studies of contaminant input
to the coastal ocean demonstrate the need for new types of sustained observations and new technology
to observe components that characterize the contaminants and their fates in the coastal ocean. A
combination of remote sensing, eularian and lagrangian measurements, various new technology cou-
pled with data assimilation and modeling are required to understand the processes.

8 A HALF CENTURY OF PHYSICAL AND BIOLOGICAL OCEANOGRAPHY IN THE
SOUTHERN CALIFORNIA BIGHT WITH EMPHASIS ON FISH SPECIES, TEMPERA-
TURE AND ZOOPLANKTON

P. E. Smith and H. G. Moser, Southwest Fisheries Science Center [NOAA/NMEFS] 8604 La
Jolla Shores Drive, La Jolla CA 92038

The California Cooperative Fisheries Investigations sea surveys have collected, identified, and cu-
rated fish larvae from 40,000 quantitative ichthyoplankton samples. The majority of the common fishes
represented as larvae in the CalCOFI ichthyoplankton time series have not been commercially fished.

ABSTRACTS 15

These species represent a Acontrol@ in assessing the relative effects of fisheries and environment on
the fish populations of the California Current region. We believe that a group of Pacific sardine
inhabited the harbors and shores of the Southern California Bight for two decades following the
collapse of the fishery in the 1960s. Beginning in 1992, the sardine population began to increase
abruptly and has emerged as a dominant epipelagic species, with a distribution stretching from southern
Baja California to Alaska. In contrast, the northern anchovy has withdrawn from its former widespread
distribution in California Current waters to the inshore regions of the Southern California Bight. During
the warm ocean regime (1977-1998) the CalCOFI larval fish time series has documented the intro-
duction and population increase of common mesopelagic species from the Eastern Tropical Pacific
and from equatorial and central water masses. The most continuous part of the CalCOFI surveys is
in the shelf waters, slope waters and California Current from the Mexican Border to San Luis Obispo.

9 ASSESSMENT OF DEMERSAL FISH AND INVERTEBRATE ASSEMBLAGES ON THE
SOUTHERN CALIFORNIA SHELF IN 1998

M. J. Allen', A. K. Groce’, D. Diener’, V. Raco-Rands', Christina Thomas‘, and Yvette Ralph‘.
‘Southern California Coastal Water Research Project, Westminster, CA 92683; *City of San
Diego, Metropolitan Wastewater Department, San Diego, CA; 7>MEC Analytical Systems, Inc.,
Carlsbad, CA 92008; *Orange County Sanitation District, Fountain Valley, CA 92008

A regional synoptic survey of demersal fish and invertebrates was conducted in 1998 on the con-
tinental shelf of the mainland (including bays) and islands of southern California. The objective of
this study was to assess the status and health of fish and invertebrate populations and assemblages. In
July-September 1998, 314 stations (S—200 m depth) were sampled from Point Conception, California
to the U.S.-Mexico International Border and at most offshore islands using 7.6-m otter trawls. The
survey collected 143 species of fish and 313 species of invertebrates. Fish and invertebrate populations
varied most by depth, with population attributes generally being lowest on the inner shelf and highest
on the outer shelf. Distinct assemblages occurred in different depth zones and in natural bays, with
island assemblages showing some differences from mainland assemblages. Fish recurrent groups in
1998 (an El Nino year) differed considerably from those typical of cool and warm regime periods in
the past. DDT in sanddab guild species exceeded predator-risk thresholds (14 ppb) in 71% of the area
on the southern California shelf. PCB exceeded predator-risk thresholds for birds and mammals in 5—
8% of the area. Relative to the early 1970s, fish and invertebrate assemblages on the southern Cali-
fornia shelf in 1998 were relatively healthy but DDT levels in sanddab guild species may pose health
risks to bird and mammal predators.

10 PAH EXPOSURE AND DNA DAMAGE IN FLATFISH FROM SOUTHERN CALIFORNIA
BAYS AND HARBORS, AND CHANNEL ISLANDS

J.S. Brown, Southern California Coastal Water Research Project, Westminster, CA, 92683, and
S.A. Steinert, Computer Science Corporation, San Diego, CA, 92110

Two species of flatfish from southern California were evaluated for exposure to polynuclear aromatic
hydrocarbons (PAHs), and DNA damage. California halibut (Paralichthys californicus) were collected
from eight bays and harbors (Ventura Harbor, Channel Islands Harbor, Marina del Rey, King Harbor,
Alamitos Bay, Long Beach Harbor, Newport Bay, San Diego Bay), and a reference site off Camp
Pendleton. Pacific sanddab (Citharichthys sordidus) were collected near four of the Channel Islands
(San Miguel Isle, Santa Cruz Isle, Anacapa Isle, Santa Barbara Isle). PAH metabolites in fish bile
were characterized using a semi-quantitative technique that measures fluorescent aromatic compounds
(FACs) in fish bile. DNA damage in fish blood cells was assessed by measuring the amount of single-
strand breaks in stained DNA using the Comet assay. The concentration of FACs was elevated in
most fish from bays and harbors, with average concentrations ranging from three to ten times greater
than FACs in reference fish. DNA damage varied by a factor of five among fish from bays and harbors.
There was no evidence of elevated PAH exposure in the Pacific sanddabs from the Channel Islands.
There was a significant association between FAC concentrations and DNA damage in California
halibut at Marina del Rey and Ventura Harbor, but not at other locations.

16 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

11 PORTS OF LONG BEACH AND LOS ANGELES BIOLOGICAL MONITORING OF SAN
PEDRO BAY

K. Green, MEC Analytical Systems, Inc. 2433 Impala Drive, Carlsbad, CA 92008

Comprehensive surveys of Long Beach and Los Angeles Harbors in San Pedro Bay were conducted
in the year 2000. These surveys represent the first harbor-wide examination of biological resources
since the extensive studies of the 1970s. The surveys also examined a greater variety of resources
than were examined in the more limited studies of smaller areas of the harbors in the 1980s and
1990s. Considerable changes have occurred in both harbors over the last couple of decades, including
deepening of navigational channels, construction of landfills and basins, creation of shallow water
habitats, and a continuation of pollution reduction measures begun in the 1960s. Results of the year
2000 surveys demonstrate that the harbors support diverse assemblages of fish, benthic invertebrates,
aquatic vegetation, and birds. Although the year 2000 surveys were conducted during a period fol-
lowing substantial changes in oceanographic conditions (i.e., dissipation of a La Nina period following
a strong El Nino event) and dredging and landfills in the harbors, the data demonstrate a continuation
of an improvement in habitat quality since the severely polluted conditions of the 1950s.

12 SOFT-BOTTOM BENTHIC INVERTEBRATE ASSEMBLAGES OF THE SOUTHERN CAL-
IFORNIA BIGHT

J.A. Ranasinghe', D.E. Montagne’, D.B. Cadien’, R.G. Velarde*, T.-K. Mikel*, R.W. Smith, S.B.
Weisberg! and A. Dalkey®. 'Southern California Coastal Water Research Project, 7171 Fenwick
Lane, Westminster, CA, 92683. 7County Sanitation District of Los Angeles County, PO. Box
4998, Whittier, CA, 90607. *City of San Diego, 4918 N. Harbor Dr., Ste 101, San Diego, CA,
92106. *Aquatic Bioassay and Consulting Laboratories, Inc., 29 North Olive Street, Ventura,
CA, 93001. °P.O. Box 1537, Ojai, CA 93024-1537. City of Los Angeles, Environmental Mon-
itoring Division, 12000 Vista del Mar, Playa del Rey, CA 90293

We identified benthic assemblages and their associated habitat differences using data from 278
uncontaminated sites sampled in the Southern California Bight in 1998. Previously, two open coastal
assemblages were identified from 1994 regional survey data; they separated on depth. We discrimi-
nated several additional assemblages primarily because we sampled additional habitats: Channel Is-
lands, bays, and the Mexican coastal shelf. In bays, we identified two assemblages based on latitude;
benthos from Dana Point Harbor to San Diego differed from those to the north and were structured
by the mat-forming clam Musculista senhousia. The assemblage in northern bays resembled the pre-
viously identified shallow and mid-depth coastal assemblages, but was distinguished by a few species
also present in the southern bays. We divided the coastal mid-depth assemblage described in 1994
into two based on sediment grain size; the portion associated with fine sediments was a subdivision
of an assemblage also found at mid-depth on the Mexican shelf and at Catalina Island. Another,
previously undiscriminated, assemblage occurred at Channel Islands sites and in coarse sediments at
mid-depths on the Mexican shelf. Finally, we discriminated another assemblage that was widespread
in very coarse, gravelly sediments. Our knowledge and understanding of benthos in the Southern
California Bight increased substantially as a result of the broader sampling effort in 1998.

13 DIVERSITY-ABUNDANCE RELATIONSHIPS IN BENTHIC HABITATS OF THE SOUTH-
ERN CALIFORNIA BIGHT

T. Mikel', D.E. Montagne?,,R.G. Velarde*, D.B. Cadien?, J.A. Ranasinghe*, S.B. Weisberg’,
R.W. Smith? and A. Dalkey®. 'Aquatic Bioassay and Consulting Laboratories, Inc., 29 North
Olive Street, Ventura, CA, 93001. *County Sanitation District of Los Angeles County, P.O. Box
4998, Whittier, CA, 90607. *City of San Diego, 4918 N. Harbor Dr., Ste 101, San Diego, CA,
92106. *Southern California Coastal Water Research Project, 7171 Fenwick Lane, Westminster,
CA, 92683. °P.O. Box 1537, Ojai, CA 93024-1537. °City of Los Angeles, Environmental Mon-
itoring Division, 12000 Vista del Mar, Playa del Rey, CA 90293

For a comparison of benthic diversity-abundance relationships in three soft-bottom habitats, 321
samples were collected at random from southern California embayments, the coastal shelf and Channel
Islands. Diversity was highest in the Channel Islands, intermediate on the coastal shelf, and lowest in

ABSTRACTS 17

embayments (means of 109, 66 and 42 taxa per 0.1m? sample, respectively). Mean abundance on the
coastal shelf was much lower than for Channel Islands and embayments (291, 651 and 658 per sample,
respectively). Thus, benthos of the bays were highest in abundance but lowest in diversity. The di-
versity-abundance relationship for the coastal shelf was indistinguishable from that for the Channel
Islands; the relationship was linear and both habitats accumulated a taxon for about every five organ-
isms collected. The pattern for samples from the bays was more variable, less linear, and taxa accu-
mulated at a slower rate; maximum abundance was nearly three times higher but numbers of taxa
were only 65% of values for islands and the coast. Diversity-abundance ratios for bay benthos only
correlated weakly with habitat variables but there was a significant (p < 0.01) correlation with abun-
dances of non-indigenous species. The low diversity-abundance ratios in embayments are at least
partly explained by a proliferation of invasive species.

14 HOW IMPORTANT ARE NONINDIGENOUS SPECIES TO THE BENTHOS OF SOUTH-
ERN CALIFORNIA EMBAYMENTS?

R.G. Velarde, City of San Diego, 4918 N. Harbor Dr., Ste 101, San Diego, CA, 92106, J.A.
Ranasinghe, Southern California Coastal Water Research Project, 7171 Fenwick Lane, West-
minster, CA, 92683 and D.B. Cadien, County Sanitation District of Los Angeles County, P.O.
Box 4998, Whittier, CA, 90607

As part of the Bight ’98 Regional Monitoring Program, 113 benthic samples were collected in
southern California embayments to assess the prevalence and evaluate the effects of nonindigenous
species. We found that nonindigenous species were prevalent throughout the area, occurring in all but
one sample. Only 25 of the 625 species we collected were considered nonindigenous but they con-
tributed an average of 10% of the species and 23% of the abundance in each sample. There was no
apparent relationship between the numbers, proportions or composition of nonindigenous species pop-
ulations and the type of vessel traffic. Three of the five most abundant species, Pseudopolydora
paucibranchiata, Musculista senhousia and Theora lubrica, were nonindigenous; other nonindigenous
species abundances were much lower. All three species were widespread. M. senhousia dominated
southern embayments while 7. /ubrica dominated Los Angeles—Long Beach Harbor and Anaheim
Bay. Large numbers of P. paucibranchiata occurred in every bay. The bivalve M. senhousia has the
greatest effect on benthic habitats. The thick mats of byssal threads that it lays down add structure
and create additional niche space for many other species. P. paucibranchiata, a polychaete worm, was
the most abundant organism in Bight °98. It builds tubes that also add structure but which have less
impact than M. senhousia because of their small size. 7. lubrica, a small bivalve, has the least effect.
It is likely that food webs today differ considerably from those existing before these invaders arrived.

15 MARINE-THE MULTI-AGENCY ROCKY INTERTIDAL NETWORK
M.E. Dunaway, Minerals Management Service, 770 Paseo Camarillo, Camarillo, CA, 93010

Regional, long-term monitoring programs provide data needed by a wide range of groups from the
public and private sector. Coordinated programs provide the added benefits of a diversified funding
source, better coordination among field researchers, data sharing and standardized field measurements.
Regional monitoring programs allow smaller entities to evaluate local changes in the context of a
broader system which is able to consider large-scale changes in the environment such as El Nino
events. Ongoing monitoring importantly allows for early detection of environmental problems. It also
provides a dynamic baseline of natural conditions prior to extreme events such as an oil spill. MA-
RINE’s focus is to determine the health of the rocky intertidal ecosystem in the Southern California
area. Seastars, abalone, mussels, surfgrass, anemones, limpets, barnacles and several varieties of algae
are monitored every fall and spring at established sites from San Luis Obispo County to San Diego
County including the offshore islands. With ten years of data at 50 sites and 2—5 years of data at
another 20 sites, changes which can be attributed to succession, recruitment and other broad patterns
now emerge. Important collaborations with other large monitoring programs such as PISCO (Partner-
ship for the Interdisciplinary Study of Coastal Oceans), provide the potential to answer important
related questions not funded by MARINE. Critical to the success of the program is a core of academic
biologists committed to ongoing monitoring and continued support by a core of agencies who value
the data being collected and are willing to work toward a common product.

18 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

16 POST-RESTORATION LONG-TERM MONITORING FOR THE BATIQUITOS LAGOON
ENHANCEMENT PROJECT

K.W. Merkel', H.D. Henderson', R-A. Woodfield’, and M. Carpenter’. 'Merkel & Associates,
Inc., San Diego, CA 92123. 7KTU+A, San Diego, CA 92103

Batiquitos Lagoon, a 234ha. closed, eutrophic lagoon in Carlsbad California was restored through
a management partnership between the Port of Los Angeles and City of Carlsbad. Since the December
1996 opening of the restored lagoon to tidal circulation, Batiquitos Lagoon has been the subject of a
10-year monitoring program to track the development of the restored system.

Over the first five year of monitoring, the rates of change in both biological and physical environ-
ments have slowed and become relatively predictable. Normal seasonal patterns of abundance, rich-
ness, and diversity within fish and bird populations have developed at relatively rapid rates of one to
two years following lagoon restoration. However, building sandbars at the lagoon entrance have ad-
versely muted tidal dynamics throughout the lagoon resulting a compression of the tidal range and a
general increase in the frequency of inundation of intertidal environments. As a result, intertidal
marshlands are restricted to higher elevations than would normally occur in a fully tidal system and
intertidal mudflats are less frequently and completely exposed than would be expected under fully
tidal conditions. Subtidal eelgrass communities and coastal salt marshes have become dominant fea-
tures of the lagoon following both natural expansion of marsh vegetation and introductions of Cali-
fornia cordgrass and eelgrass to the system where both species have long been absent. The develop-
ment of vegetation communities within the lagoon occurred through delayed and punctuated events
following periods of physical and chemical environmental stabilization.

17 ATMOSPHERIC DEPOSITION OF TRACE METALS TO SANTA MONICA BAY

K. Schiff, L. Tiefenthaler, Southern California Coastal Water Research Project, Westminster,
CA, and K. Stolzenbach, R. Lu, R. Turco, S. Friedlander, University of California Los Angeles,
Los Angeles, CA

There are numerous sources that contribute pollutants to Santa Monica Bay. Some sources (i.e.
POTWs) are well-characterized and inputs to the Bay are: well-known. Other sources, such as atmo-
spheric deposition, have not been well-characterized and its inputs are almost completely unknown.
Aerosol samples were collected for particulate mass.and trace metal concentrations every six days
throughout one year in the Santa Monica Bay watershed and at eight satellite locations within the
airshed, but outside of the watershed. Samples of wet deposition were collected for the entire wet
season. Finally, seasurface microlayer samples were collected across a grid of stations to determine
the amount of surface area affected by atmospheric deposition. Concentrations of metals were lowest
at the Santa Monica Bay site relative to other sites in the airshed and most deposition was likely from
sources within the watershed. Aerial deposition had some impact on Bay water quality; trace metal
concentrations were enriched as much as 80-fold in the seasurface. microlayer across one-third of the
Bay. Most deposition occurred during dry weather; wet deposition represented as little as 2% of the
total annual load for most metals. Atmospheric deposition of chromium, copper, nickel, lead, and zinc
using a locally-developed atmospheric transport and deposition model were 15, 38, 53, 3, and 167
metric tons annually, respectively. These estimates represent between 40 and 60% of the combined
mass emissions from all sources including POTWs, industrial discharges, and urban runoff.

18 CHARACTERISTICS, FORMATION MECHANISMS AND CHEMICAL COMPOSITION
OF ULTRAFINE PARTICLES IN VARIOUS LOCATIONS OF THE LOS ANGELES BASIN

Constantinos Sioutas, Si Shen, Michael D. Geller, Chandan Misra and Seongheon Kim, Uni-
versity of Southern California, Department of Civil and Environmental Engineering, 3620 South
Vermont Avenue, Los Angeles, CA 90089

Ultrafine particulate matter (PM) consists of particles mostly emitted by combustion sources as well
as formed during gas-to-particle formation processes in the atmosphere. Various studies have shown
these particles to be particularly toxic, The very small mass of these particles has posed a great
challenge in determining their size-dependent chemical composition using conventional aerosol sam-
pling technologies. This paper presents results from a study conducted in two urban areas of Southern

ABSTRACTS 19

California in order to examine the effect of different sources and formation mechanisms on the size
distribution and temporal trends of ultrafine particles. From semi-continuous measurement of size
distribution of ambient aerosols as well as time-integrated sampling of particles, the temporal and
diurnal trends in the behavior of ultrafine particles were conducted to better understand the formation
mechanisms in different locations of an urban metropolitan area. Results showed that a western site,
located in central Los Angeles, is appropriately characterized as a source site with constant primary
emissions. In contrast, ultrafine and accumulation modes PM in a receptor site were found to originate
mostly from secondary reactions, which are more pronounced during the warmer months of the year
particularly during the warmer season of the year, between April through October. The differences
observed in the ultrafine particle distribution and temporal trends clearly demonstrated that mecha-
nisms other than direct emissions play an important role in the formation of ultrafine particles in
receptors sites of the Los Angeles Basin.

19 AUTOTOMY: NOVEL PROTECTION FROM MERCURY TOXICITY IN AQUATIC OLI-
GOCHAETE WORMS

Doris Vidal. Southern Caltfornia Coastal Water Research Project. Toxicology Department. West-
minster CA 92683-5218

Aquatic oligochaete worms are commonly used as tools in toxicity testing as well as in sediment’s
health assessments. Oligochaete worms are generally considered pollution tolerant, but little research
has been made to help us_understand the mechanisms used by these ‘tolerant’? worms to survive
pollutant exposure. The present research suggests that changes in the behavior of tolerant worms are
an important component of the many levels of response to contaminants that promote the worms’
survival. We investigated autonomy behavior (reflex action by which the tail segments of the worms
brake off and the missing segments are later regenerated) in Sparganophilus pearsei worms as a
reaction to mercury stress. The behavior was assessed and compared among three populations with
different mercury sensitivities. Mercury accumulation in different body segments was measured. The
results of these experiments suggest these worms may use autotomy as a mechanism of mercury
detoxification.

20 EQUAL LOADS OF NUTRIENTS ADMINISTERED TO MACROALGAE VIA PULSES OF
DIFFERING FREQUENCY AND MAGNITUDE AFFECT GROWTH AND TISSUE NUTRI-
ENTS OF EVTEROMORPHA INTESTINALIS AND ULVA EXPANSA

Krista Kamer', Rachel L. Kennison’, and Peggy Fong’. 'Southern California Coastal Water
Research Project, Westminster CA 92683. 7University of California, Los Angeles, Department
of Organismic Biology, Ecology and Evolution, Los Angeles CA 90095

Macroalgae such as Enteromorpha intestinalis and Ulva expansa are highly successful in estuarine
systems, in which nutrient inputs can range from chronic, daily loads to episodic pulses. We investi-
gated the effect of the timing of nitrogen (N) supply on the growth and tissue nutrient dynamics of
E. intestinalis and U. expansa while holding N supplies constant. Over a 28-day period, algae were
given equal supplies of NO;-N (1988 mmol, or 28 mg) via pulses of different magnitude and frequency.
Doses given to 10 g of algae in | L seawater were: 71 mmol (1 mg) daily, 497 mmol.(7 mg) weekly,
994 mmol (14 mg) bi-weekly, or 1988 mmol (28 mg) monthly. Phosphorus was also added in a 10:
1 (molar) ratio. Growth was highest for both species when N was added most frequently (daily).
Tissue N and P content were also highest when nutrients were added daily. Overall, EF. intestinalis
grew more than U. expansa, however U. expansa had much greater tissue N content than E. intestin-
alis. E. intestinalis and U. expansa displayed extremely high uptake rates over the course of the
experiment. Within 24 h, both algae depleted the water column of the first daily dose, and in the other
treatments, E. intestinalis removed 460-580 mmol NO, from the water column, and U. expansa
removed 510—910 mmol NO,. The ability of these species of algae to take advantage of increased
frequency of nutrient supply may, in. part, explain their success in coastal systems subject to chronic
nutrient inputs.

20 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

21 MORPHOLOGICAL VARIATION AND PATTERNS OF REPRODUCTION AND RE-
CRUITMENT IN LOWER INTERTIDAL POPULATIONS OF THE KELP EGREGIA MEN-
ALESTT (TURNER) ARESCHOUG

Henkel, Sarah K. and Murray, Steven N. Department of Biological Science, California State
University, Fullerton, PO Box 6850, Fullerton, CA 92834-6850

Egregia menziesii (O. Laminariales) is an important habitat-structuring component of shallow, ben-
thic communities throughout central and southern California. Morphological variation in this species
is high, particularly in the lateral blades that distichously cover the flattened branches. Fertile sporo-
phylls are believed to be produced throughout the year, but to be most abundant between April and
November. However, spatial and temporal patterns of thallus morphology and sporophyte reproduction
have not been investigated in Southern California. We studied lower intertidal populations of E.
menziesii at three southern California sites separated by <16 km. Growing axes (n = 9) were collected
monthly to quantify sporophyll production and the frequencies of different types of lateral blades.
Band transects were surveyed quarterly to determine temporal patterns of sporophyte recruitment.
Sporophylls were found throughout the year, but sporophyll densities showed a strong peak in winter
(December) at all three sites. Sporophyte recruitment began in late February and peaked in June,
suggesting a gametophyte period of approximately 6 months. Lateral blade morphology at the three
sites varied in a consistent pattern and was related to axis length; most thalli initially developed
spatulate lateral blades and then produced narrower, filiform laterals. Thalli subjected to intense grazing
pressure had shorter axes and were dominated by spatulate blades, while those growing under low
grazing pressure exhibited longer branches, densely covered with filiform laterals. Observed changes
in the frequencies of morphologically variable lateral blades along E. menziesii axes hypothetically
affect productivity, susceptibility to grazing, and thallus drag in this shallow water kelp.

22 HABITAT ASSOCIATIONS OF STEELHEAD TROUT IN A SMALL STREAM NEAR THE
SOUTHERN EXTENT OF THEIR RANGE

A. P. Spina. National Marine Fisheries Service, Southwest Region, Long Beach, CA 90802

Habitat associations of steelhead trout Oncorhynchus mykiss are generally well known for popula-
tions in northern territories, but nearly nothing has been documented concerning habitat associations
of steelhead in southern landscapes. I assessed use of microhabitat and mesohabitat by three age
groups of wild juvenile steelhead in a small coastal stream in south-central California (35° N). The
objectives of this study were to describe use of various habitat types (run and pool) and characteristics
(depth and velocity), and to investigate relationships between spatial variation in density of juvenile
steelhead and habitat properties (depth, habitat area, riparian canopy and density of older conspecifics).
Generally, the results show that use of habitat by juvenile steelhead was size or age dependent, and
was influenced by water depth and to a lesser extent focal point velocity. Spatial variation in the
density of the age groups was related to the arrangement of certain habitat properties; large deep pools
may be valuable in particular to age-1 and older steelhead. Because the habitat used by age-O steelhead
may not necessarily be suitable for age-1 and older steelhead, the findings support the belief that
multiyear freshwater residence of steelhead requires habitat that is appropriate for all age groups.

23 IN SITU MONITORING OF GASTRIC pH CHANGES ASSOCIATED WITH FEEDING IN
LEOPARD SHARKS

Yannis P. Papastamatiou and Christopher G. Lowe, Department of Biological Sciences, Cali-
fornia State University Long Beach, 1250 Bellflower Blvd., Long Beach CA 90840

Surprisingly little is known about feeding periodicity in sharks. We monitored changes in gastric
PH as a possible indicator of feeding in leopard sharks (Triakis semifasciata). An adult leopard shark
was fed a pressure insensitive pH probe with attached data-logger (110 mm X 10 mm — 80 g) and
was subsequently fed different rations of squid over a 14 d period. The stomach remained strongly
acidic over the duration of the experiment, except during feeding bouts, which resulted in a rapid
increase in pH followed by a gradual decrease until returning to pre-prandial levels (mean pH lhr
before meal was 1.6 + 0.04 (SD), lhr after meal was 2.71 + 0.51). Ration size was positively
correlated with the time needed for gastric pH to return to pre-prandial levels. To determine the effects

ABSTRACTS 21

of the probe on gastric pH, stomach fluid samples were taken from 10 non-instrumented sharks at
different time intervals after being fed a meal of squid. Gastric pH increased to 3.32 + 0.38 1-hr after
feeding and gradually decreased to 2.04 + 0.27 after 72-hr. These data support in situ observations
made using the probe and suggest that pH changes could be used to determine feeding events in the
wild.

24 ONTOGENETIC RESPONSES TO TERRESTRIAL DIETS IN A NEOTROPICAL FISH:
GUT MORPHOLOGY AND DIGESTIVE ENZYME ACTIVITY IN BRYCON GUATEMA-
LENSIS (CHARACIDAE)

K.E. Drewe and M.H. Horn. California State University, Fullerton, Department of Biology,
Fullerton, CA 92834

The characid fish Brycon guatemalensis consumes insects as juveniles and fruits and leaves as
adults. Gut structure and function may be expected to change with this ontogenetic shift from carnivory
to herbivory. So, we compared gut length (in progress), pyloric caeca number and arrangement (in
progress), and biochemical activity of four digestive enzymes (pepsin, trypsin, amylase and lipase) in
juvenile (40-80 mm SL) and adult (242—414 mm SL) fish collected from the Rio Puerto Viejo, a
tropical rain forest stream in northeastern Costa Rica. Activities (IU/ g tissue) of pepsin and trypsin
were significantly higher in juveniles than adults, whereas amylase activity was significantly greater
in adults than juveniles. Lipase activity did not differ between age classes. Our results at this point
show that the differences between juveniles and adults in gut length and digestive enzyme activities
match those expected for carnivores vs. herbivores and indicate that B. guatemalensis is ontogeneti-
cally specialized to digest each component of its terrestrial diet.

25 DIEL MOVEMENT PATTERNS OF THE OCEAN SUNFISH, MOLA MOLA: A PRELIMI-
NARY REPORT

D. Cartamil and C. Lowe. California State University, Long Beach, Department of Biological
Sciences, Long Beach, California, 90840

We used temperature and depth-sensing acoustic transmitters to track the movements of four ocean
sunfish near Catalina Island, California. We tracked fish continuously for 24—48 h periods, and con-
currently deployed a CTD every 90 minutes to characterize the water column. Geographical position
was determined by GPS at 3-minute intervals during tracks, and was analyzed in relation to fish depth
and temperature, oceanographic data, and time of day. Ocean sunfish traveled a mean distance of
30.11 + 9.16 km over a 24 h period. Rate of movement was significantly lower for 6 hours following
sunset (p<0.001) than at other times of day. Ocean sunfish inhabited depths ranging from the surface
to 392 m, and generally displayed a trend towards diel vertical migration. The diel depth distribution
patterns of ocean sunfish may make them highly susceptible to the drift gillnet fishery off southern
California, of which they comprise 26% of the total catch.

26 INCIDENCE OF SALMONELLA IN FREE RANGING IGUANID LIZARDS OF SOUTH-
ERN CALIFORNIA

Jeffery Burkhart, Ron Fauntleroy, and Kelly Spencer, Department of Biology, University of La
Verne, La Verne, CA 91750

Considerable study has been devoted to investigating the incidence of Salmonella in the gut of
captive reptiles, however limited data are available for free ranging populations. This study investigated
the frequency of Salmonella in cloacal samples drawn from five species of southern California iguanid
lizards: Sceloporus occidentalis longipes, S. g. graciosus. S. o. orutti, S. magister uniformis, and Uta
stansburiana. Sceloporus occidentalis was the principle species of investigation. In samples drawn
from 96 specimens, 55% (N = 33) of females, and 41% of males (N = 63) tested Salmonella positive.
No positive tests were found in cloacal swabs taken from S. graciosus (N = 20), nor U. stansburiana
(N = 10). Salmonella was found in three of four specimens of S. orcutti.

When juvenile lizards are omitted from the frequency calculations for S. occidentalis, Salmonella

WN
N

SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

presence was found to differ significantly different between the sexes (P<0.05). Further, Salmonella-
infected female S. occidentalis longipes were found to be significantly larger in body mass (P<0.02),
than non-infected females. Males appear to be larger as well, however the differences were only
significant at the 0.10 probability level. Causality for the difference in body size is explored and is
proposed as a topic for future study.

27. OIL IMPACT ON GROWTH OF SALICORNIA VIRGINIA UNDER CONTROLLED TID-
AL CONDITIONS

C.Y. Chen, D.D. Portugal, T. Zuniga and A.H.B.M. Wijte. California State University, Long
Beach, Department of Biology, Long Beach, CA, 90840

Salicornia virginica is a slow growing salt marsh plant species that grows at the lower marsh
elevations. In a greenhouse experiment, S. virginica plants were exposed to an oil treatment of 2 L/m?
in a microcosm that included a tidal regime, which inundated the plants twice daily. In a six-week
experiment we examined plant biomass and succulence under oiled and control conditions. In a twelve-
week experiment we examined the growth of S. virginica under oiled and control conditions. Addi-
tionally we examined the ability of S. virginica to recover from oiling by moving plants exposed to
oil for six weeks to a clean microcosm for the remaining six weeks. After six-week exposure, shoots
and roots were not significantly affected. Shoot succulence, however, was negatively affected by oil.
Additionally, there was a significant interaction between the effects of oiling and inundation levels on
shoot succulence, indicating a beneficial effect of tidal washing during oil contamination. All S.
virginica exposed for twelve weeks died, shoots were 100% senesced. Those transplanted from the
oiled to the clean microcosm after six weeks to recover for an additional six weeks showed growth
of green shoots at the terminal end of the shoots affected during the six weeks of oiling. S. virginica
after twelve weeks of oiling had all senesced. Roots after six-week recovery showed limited re-growth
following their six-week oiling. First physiological impact on S. virginica affects its succulence. It
can recover after at least six weeks of oil exposure.

28 EXAMINATION OF RECRUITMENT PATTERNS IN KELPBASS, PARALABRAX
CLATHRATUS, BY THE ANALYSIS OF MITOCHONDRIAL DNA CONTROL REGION
SEQUENCES

Christina W. Luzier and Raymond R. Wilson, Jr., California State University, Long Beach,
Department of Biological Sciences, Long Beach, CA 90840

Potential benefits of marine protected areas (MPA) include increased biomass, species diversity, and
enhanced recruitment to the MPA and to adjacent non-protected areas. Whereas MPAs can increase
biomass and species diversity within their boundaries, any effect on recruitment has yet to be observed.
Knowledge of recruitment patterns deriving from MPAs could help determine their effectiveness as a
fishery management tool. We obtained and analyzed 123 mtDNA control region sequences (420 bp)
of juvenile kelp bass, Paralabrax clathratus, recruiting near two MPAs to establish the genetic makeup
of the recruitment pulses. If an MPA was enhancing recruitment to adjacent areas, one might expect
to see recruitment pulses dominated by groups of siblings and half-siblings spawned from one to few
females in the area, possibly signaling locally derived recruitment. Sibling-dominated recruitment
would potentially be indicated by a significant drop in the proportion of singleton haplotypes relative
to an adult sample. Homogeneity tests for singleton counts among three separate sets of recruiting
juveniles, versus adults, found no significant reductions, indicating that P. clathratus juveniles probably
recruit in genetically well-mixed groups instead of sibling-dominated ones. The results do not support
suggestions that MPAs significantly enhance adjacent areas through recruitment.

29 BEHAVIORAL RESPONSES OF SCALLOPED HAMMERHEAD SHARKS, SPHYRNA
LEWINT, AND LEOPARD SHARKS, TRIAKIS SEMIFASCIATA, TO PULSED, DIRECT
CURRENT ELECTRICAL FIELDS

M.M. Marcotte. California State University, Long Beach, Department of Biological Sciences,
Long Beach, CA, 90840

Electrical shark deterrents might be a less harmful way to protect people and equipment than
meshing beaches or fishing for sharks. The use of strong electrical fields as a shark deterrent has

ABSTRACTS 23

shown promise, but has been poorly documented. Behavioral responses of sharks to pulsed, direct
current electrical fields were quantified in the laboratory. Scalloped hammerhead sharks (SH) and
leopard sharks (LS) were baited to an odor source when an electrical field was both off and on. A
head twitch behavior was elicited in SH and LS at average voltage gradient thresholds of 4.16 + 0.59
SD V/m and 4.30 + 0.78 SD V/m, respectively. A shimmy behavior was elicited in some SH at an
average threshold of 5.54 + 1.55 SD V/m. A retreat behavior was elicited in SH and LS at an average,
maximum threshold of 18.50 + 13.27 SD V/m and 9.64 + 10.28 SD V/m, respectively, which was
indicative of the effective deterrent threshold and was higher than previously reported. Both SH and
LS remained significantly farther away and spent significantly less time near the odor source when
the electrical field was on than when the electrical field was off, although the sharks’ responses were
highly variable.

30 PHYLOGENY AND BIOGEOGRAPHY OF THE SERANNID FISH GENUS EPINEPHELUS

M. T. Craig. Scripps Institution of Oceanography. 9500 Gilman Dr. Mail Code 0208, La Jolla,
CA 92093-0208

The genus Epinephelus is comprised of 99 species of perciform fishes commonly known as groupers.
This large and diverse group of fishes is distributed in tropical and sub-tropical waters worldwide.
Although being recognized in the taxonomic literature for more than 200 years, recent molecular
evidence suggests that this genus is paraphyletic and in need of revision (Craig, et al. 2001). Mito-
chondrial DNA sequences for 83 species of epinepheline serranids were gathered to determine phy-
logenetic relationships within Epinephelus and allied genera. The data confirm that Epinephelus is
indeed a paraphyletic genus. Biogeographic interpretations of this data suggest that the new world
may be the location of origination of many clades within this diverse group, and that the main radiation
of many grouper lineages may have taken place during the miocene.

31 FISH SPECIES COMPOSITION FROM THE SEAFOOD MARKET OF ENSENADA, BAJA
CALIFORNIA, MEXICO (2000-2001)

Hernandez-Hernandez, Alejandra Y Jorge A. Rosales-Casian, Departamento de Ecologia, Grupo
de Ecologia Pesquera Centro de Investigaci6n Cientifica y Educaci6n Superior de Ensenada
(CICESE) Km 107 carretera Tijuana-Ensenada, Ensenada Baja California, México. U.S. Mail-
ing: P.O. Box 434844, San Diego California 92143-4844 U.S.A.

From October 2000 to September 2001 we study the specific composition of commercialized fish
species in the Seafood Market of Ensenada, Baja California, Mexico. Our objectives were to determine
the fish species, the number of individuals, the monthly variation and the size of the fishes. A total
of 106 fishstands were sampled, and were counted 7,928 individuals with a total biomass of 6,702
Kg. A number of 54 species belonging to 47 genera and 26 families were identified. The families
represented by greatest number of species were Sciaenidae (nine), Serranidae (four), y Labridae (three).
The monthly fish species varied from 13 (during the months of December, March and September) and
27 (during the month of July). According to relative abundance of commercialized individuals during
the study, three groups of species were conformed, which five species and one family represented
more of 5% of the samples, 13 species represented between the | and 5% and 33 less of 1%. The
most abundant fish species commercialized during the period of study were: Caulolatilus princeps
(21%), Paralabrax nebulifer (10%), Amphistichus argenteus (7%), the family Scorpaenidae (6.2%),
Paralabrax auroguttatus (6%) y Mugil cephalus (6%). The species C. princeps, Seriola lalandi, Ron-
cador stearnsii and Menticirrhus undulatus, contributed with the 56,4% of the total biomass. For each
one of the species with more of 5% in the samples, we present information of the commercialized
sizes. Do not exist regulation that establish minimum statures of capture for the fish species, except
M. cephalus, which was commercialized during the period of study below their minimum stature of
capture.

24 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

32 POLYCHAETOUS ANNELID ASSEMBLAGES ASSOCIATED WITH SEDIMENTS NEAR
SEVEN SHALLOW WASTEWATER OUTFALLS ALONG THE TIJUANA-ENSENADA
COSTAL CORRIDOR IN NORTHERN BAJA CALIFORNIA, MEXICO

V. Rodriguez-Villanueva', R. Martinez-Lara* and V. Macias-Zamora!. 'I.1.0. Universidad Au-
t6noma de Baja California. Km 107 Carretera Tijuana-Ensenada. Apartado Postal 453. Ensen-
ada, B.C. México; Marine Biology Laboratory, City of San Diego Ocean Monitoring Program.
4918 North Harbor Drive, Suite # 101, San Diego, CA 92106. USA

In July 2001, 21 benthic stations were sampled at depths between 5 and 13m, ranging from Tijuana
to Punta Banda, Baja California, México. The aim of this study was to describe the species distribution
and structure of the polychaete communities associated with soft bottom habitats that occur near seven
known point sources of wastewater discharge in the region. A total of 1,637 polychaetous annelids
representing 31 families and 84 species were identified, which constituted 60% of all macrofauna
sampled. Most abundant families were Spionidae, Owentidae, Cossuridae, and Ampharetidae, which
accounted for 64% of the total polychaete fauna. Families with highest species richness were Spion-
idae, Cirratulidae, Lumbrineridae, and Terebellidae. The seven most abundant species were Owenia
fusiformis, Cossura sp A, Polydora cirrosa, Ampharete labrops, Spiophanes bombyx, Mediomastus
spp., and Armandia brevis, representing 63% of all polychaetes. Nephtys caecoides and Spiophanes
duplex occurred at most stations, but were not abundant. Patterns of polychaete abundance and di-
versity varied from north to south. The area from Tijuana to Punta Descanso (north zone) supported
lower numbers of polychaetes and lower diversity (H’), than the south zone between El Sauzal to
Punta Banda. Six species described as opportunistic were located in the south zone, including Capitella
capitata, Cossura sp, Dorvillea annulata, Armandia brevis, Polydora cirrosa, and Notomastus tenuis.
Classification and ordination analysis based on species composition and abundance data recognized
three distinct assemblages of stations within the southern zone. PCA analysis applied to environmental
parameters resulted in three station groups defined by sediment grain size, and total organic carbon.

33 POPULATION SYSTEMATICS OF THE CAROLINA ANOLE, ANOLIS CAROLINENSIS
VOIGT (IGUANIDAE: POLYCHROTINAE): GEOGRAPHIC VARIATION IN MORPHOL-
OGY

W.C.H. Chun! and J.W. Archie”. 'University of California, Department of Organismic Biology,
Ecology, and Evolution, Los Angeles, CA, 90095; and ?California State University, Department
of Biological Sciences, Long Beach, CA, 90840

The Carolina or green anole, Anolis carolinensis, has an extensive range throughout the Coastal
Plain and contiguous regions of the southeastern United States. A considerable amount of morpho-
logical variation has been reported for this species but has never been fully quantified. In order to
study the population systematics of A. carolinensis, we gathered a data set of 22 morphometric and
meristic characters from 685 preserved specimens. Males and females from the study populations were
separated into 17 locality-based, operational taxonomic units (OTUs) spanning the range of the species.
OTU identification and selection were based on specimen availability, possible physiographic distri-
bution barriers, and geographic variation in other regional herpetofauna. Specimens of A. porcatus
from Florida and Cuba were selected as an outgroup in a cluster analysis of the data using the neighbor-
joining method. The results of this study reveal distinct morphological differences between mainland
populations of A. carolinensis and populations from peninsular Florida, with a possible line of de-
marcation at or near Alachua County, Florida. While previous studies have indicated a genetically
distinct population in southwestern Florida, we recommend that taxonomic separation of the entire
peninsula be withheld at this time, pending further study.

34 SALT TOLERANCE AND REMEDIATION POTENTIAL OF SALIX LASIOLEPIS: A NA-
TIVE CALIFORNIA WILLOW

A. Ferrus-Garcia, CM Vadheim, J. Roberts. Department of Biology, CSU Dominguez Hills,
Carson CA 90747

Urbanization and agricultural practices have increased salinity levels in many S. California rivers/
streams. Increased salinity levels may limit the success of trees commonly used to remediate degraded

ABSTRACTS

N
N

wetlands and riparian areas. We are therefore studying the salinity tolerance of several native S.
California willows including Salix lasiolepis (Arroyo willow). In addition, given S. lasiolepis’ phe-
notypic plasticity, we are studying salinity tolerance of S. /asiolepis from three different locations to
identify populations with higher salinity tolerance. First we conducted small pilot studies of the salinity
tolerance of asexually propagated S. /asiolepis cuttings grown in soilless medium under greenhouse
conditions. Salt content of the medium was altered using dilute solutions containing 0, 50, 100, and
200 mM NaCl. At 9 weeks, differences in new growth weight among sites were observed. Mean new
growth weight of control cuttings ranged from 0.12 to 0.24g depending on the population. Overall,
mean new growth for each population decreased with increasing NaCl concentrations. However, new
roots were not as negatively affected as new shoots and leaves were. Moreover, for two Salix lasiolepis
populations, mean root dry weight of cuttings exposed to 100 mM NaCl was within 10% of their
respective controls (109% and 96%). This preliminary study suggests that specific populations of
Arroyo willow may be better suited for revegetation of riparian sites. It also suggests that salt tolerance
of Salix lasiolepis may be enhanced with NaCl pretreatment. In the next phase of our study, cuttings
from three populations will be pretreated with NaCl and then exposed to 0, 50, and 100 mM NaCl.

35 NORTHERN ORANGE COUNTY FALL 2001 WEATHER SUMMARY

G.P. Hannes, California State University, Fullerton, Department of Geogrpahy, Fullerton, CA
92634

This poster displays the fall 2001 maximum and minimum daily air temperatures and the monthly
average maximum air temperatures recorded at Yorba Linda, California, for the years 1988 through
2001. Also shown are the fall 2001 monthly surface and 500 millibar pressure maps for the northern
hemisphere.

During October 2001, Yorba Linda recorded the third lowest monthly average maximum air tem-
perature, while November 2001 had the second lowest average since the La Nina year of 1988. The
fall started off with the formation of a 500 mb ridge pattern over the western portion of the United
States and this ridge was later replaced by a trough system in the month of November and December.
The presence of an upper level trough system allowed a series of surface storms to pass through
southern California and caused the lower air temperatures. Generally, La Nina and El Nino events
have an impact on west coast weather which will be described in the poster presentation.

36 TROPHIC LEVELS AND HEAVY METAL CONCENTRATIONS OF TERNS AT TWO
CALIFORNIA NESTING COLONIES

M.H. Horn', A.Z. Mason”, D.R. Smith', E.A. Logothetis* and C.T. Collins”. 'Department of
Biological Science, California State University, Fullerton, Fullerton, CA 92834 *Department of
Biological Science, California State University, Long Beach, Long Beach, CA 90840, 71810
Perry Avenue, Wilmington, NC 28403

We determined the stable carbon and nitrogen isotope values and heavy metal concentrations for
Caspian Tern (Sterna caspia), Elegant Tern (Sterna elegans) and Forster’s Tern (Sterna forsteri) and
their fish prey at the Bolsa Chica Ecological Reserve in southern California and, except for Elegant
Tern, in south San Francisco Bay during the 1997-1999 breeding seasons. *'°C and *!°N values and
concentrations of a wide variety of metals were obtained for abandoned eggs and livers of dead chicks
of these tern species and for several prey species. In this presentation, we focus on a comparison of
Cu (copper), Zn (zinc), Hg (mercury) and Cd (cadmium) concentrations in eggs vs. livers and on the
relationship between Hg level and *!°N value within and among tern species. A significant increase
(t-test) in the concentrations of Cu and Zn from eggs to livers was observed inmost cases for the tern
species at both sites. Conversely, Hg levels, with one exception, were significantly higher (t-test) in
the eggs than in the livers. The small range of *'°N values indicates that the birds feed on virtually
the same trophic level and, thus, Hg biomagnification was not apparent. Cd concentrations were
essentially at detection limits for all samples analyzed indicating limited bioavailability. Our results
show marked differences in the concentrations of the four metals in eggs and livers, which appear to
reflect not only differences in their bioavailability at the two sites but also in their requirements for
physiological processes.

26 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

37 ACANTHOCHONDRIA SP. A, A NEW SPECIES OF PARASITIC COPEPOD (POECILOS-
TOMATOIDA: CHONDRACANTHIDAE) ON THE CALIFORNIA HALIBUT, PARALI-
CHTHYS CALIFORNICUS, FROM SANTA MONICA BAY, CALIFORNIA

Julianne Kalman. Department of Organismic Biology, Ecology, and Evolution, University of
California, Los Angeles (UCLA), Los Angeles, CA 90095-1606

A new species of parasitic copepod, Acanthochondria sp. A, is described from the California halibut,
Paralichthys californicus (Ayers), collected from Santa Monica Bay, California. A total of 7 nono-
vigerous and 22 ovigerous females (each carrying a male) was collected from the gill cavity of the
California halibut. This species of parasitic copepod can be distinguished from other species of Acan-
thochondria by the large body size, long posterior processes, and the structure of the legs. This is a
relatively large copepod (almost 7.0 mm in length) and the posterior processes are much longer than
those of other species of this genus. Legs | and 2 have relatively long rami with the endopod noticeably
longer than the exopod. This species exhibits the characteristic sexual dimorphism of this genus, with
the female (approximately 7.0 mm) noticeably larger and morphologically distinct from the male (less
than 1.0 mm).

38 PARASITE-MEDIATED SEXUAL SELECTION OF GREEN SWORDTAILS, X7PHOPHO-
RUS HELLERI

R. Lavie and C. Hogue, California State University, Northridge, Department of Biology, North-
ridge, CA, 91330

Hamilton and Zuk (1982) introduced the concept of parasite-mediated sexual selection using the
‘““good gene”’ theory, proposing that females preferred males with more pronounced secondary sexual
characteristics because they were indicators of physically fit males possessing parasite-resistant genes.
The contagion indicator hypothesis (Able 1996) branched from the “‘good gene”’ theory suggesting
that females preferred non-parasitized males due to direct benefits of avoiding parasite contraction
from courting males. Conflicting support and rejection of these theories have caused researchers to
question their validity. Moller (1990) proposed that there might be flaws in previous researchers’
methodology. Past researchers have used macroparasites as a measurement of an organism’s fitness
level without taking into account that they might be benign to the host’s fitness, as well as uninten-
tionally ignoring the effects of the microparasites that may also simultaneously inhabit the host. An
immune analysis following an immune initiation would allow for an actual quantification of male
fitness (Moller 1999). The intent of this study is to perform immune analyses via white blood cell
counts from the peripheral blood and spleen of Green Swordtails, Xiphophorus helleri, following an
immune initiation, along with parasite level counts of Dactylogyrus intermedius as a means of mea-
suring male fitness. These techniques in addition to courtship studies will be used to determine if (1)
non-parasitized males are in fact out competing parasitized males, (2) if immune analyses are better
methods of quantifying a male’s fitness level than parasite counts, and (3) if parasitism is a driving
force for sexual selection.

39 THE BENTHIC COMMUNITY OF SAN DIEGO BAY

E. C. Nestler, D. Pasko, and T. D. Stebbins. Marine Biology Laboratory, City of San Diego
Ocean Monitoring Program, 4918 N. Harbor Drive, Suite #101, San Diego, CA 92106, USA

Benthic infauna and sediment samples were collected at 46 stations in San Diego Bay, California
as part of the coastal ecology component of the Southern California Bight 1998 Regional Monitoring
Survey (Bight ’98). All stations were selected randomly using the USEPA probability-based EMAP
design and ranged in depth from 3 to 15.6 m. Infaunal community structure was summarized for each
station and then compared to various environmental and sediment parameters (e.g., depth, % fines,
total organic carbon, nitrogen, and several contaminants of concern). Ordination and classification
analyses were also performed to examine the overall similarity of benthic assemblages in the bay. A
total of 38,187 macrobenthic organisms representing 341 taxa were identified. More than 27% of these
represented rare or unidentifiable taxa that occurred only ance. Two species of polychaetes, the cap-
itellid Mediomastus sp (likely a species complex) and the spionid Prionospio (Prionospio) hetero-
branchiata, were collected at all 46 stations. Mediomastus sp was also the numerically dominant taxon,

ABSTRACTS eae |

comprising 13% of all organisms collected (n = 4,978 individuals). An introduced bivalve, Musculista
senhousia, was the second most abundant taxon (n = 3,931 individuals), followed by the sabellid
polychaete Euchone limnicola (n = 3,894 individuals). Preliminary analyses suggest that tidal flushing
may be the primary factor influencing the distribution of benthic assemblages or sub-assemblages
throughout the bay. This survey provides valuable baseline data against which future changes in the
ecology of the subtidal benthos of San Diego Bay may be assessed.

40 PROBABLE LATERITE IN THE PALEOCENE LAS VIRGENES SANDSTONE, SOLSTICE
CANYON, SANTA MONICA MOUNTAINS, CALIFORNIA

G.R. Noriega, H.O. Hernandez, Dr. P. Ramirez, California State University Los Angeles, De-
partment of Geological Sciences, Los Angeles, CA, 90032

A nine-meter thick Paleocene paleosol present in the Las Virgenes Sandstone, Santa Monica Moun-
tains, California, probably represents an ancient soil formed in a tropical climate. The paleosol is
interbedded with sandstones and mudstones deposited in a fluvial environment. Four zones occur in
the paleosol. The lowermost Zone | is a reddish fining upward sequence of weathered sandstone (60%
quartz, 20% feldspar, and 20% kaolinite) and mudstone. Zone 2 is mottled white and purple and
consists of 70% quartz and 30% kaolinite. Iron pisolites in a matrix of 25% quartz and 75% kaolinite
comprise Zone 3. The uppermost Zone 4 consists of iron pisolites in a matrix of 15% quartz and 85%
kaolinite. Sandstones above and below the paleosol contain 60% quartz, 25% feldspar, and 15%
kaolinite and are compositionally similar to Zone 1, indicating the paleosol formed on sandstones.
The upward decrease in quartz, loss of feldspar and increase in kaolinite results from feldspar alteration
to kaolinite and to quartz dissolution as the paleosol formed. Iron pisolites resulted from iron accu-
mulation as iron minerals were leached. Zones identified in the paleosol are similar to those of lateritic
soils that develop mostly in tropical climates.

4l ASSESSMENT OF THE HEALTH OF KELP HABITATS ALONG THE NORTH COAST OF
SANTA MONICA BAY

B. Reed', P. Fong’, and J.R. Smith”. 'Santa Monica BayKeeper, 7University of California, Los
Angeles (Funded by the Santa Monica Bay Restoration Foundation)

The distribution and abundance of kelp forests flanking Santa Monica Bay are spatially and tem-
porally patchy, especially along Malibu, and have shown a decline over the past 20 years. To assess
the health of kelp habitats, a suite of physical and chemical factors were investigated in Malibu to
determine their influence on kelp distribution and abundance. These factors were also measured in
Palos Verdes (PV), an area where kelp abundance has remained relatively high. Surveys showed that
adult kelp abundance was similar in Malibu and PV presumably because we chose patches where kelp
was abundant. However, sub-adult (< Im) and juvenile kelp abundance was higher in Malibu than
PV suggesting a higher early survivorship. These results also suggest that Malibu kelp beds were not
recruitment limited. The availability of hard rock surfaces was found to be higher in PV. In contrast,
Malibu substrate was composed of mostly sediment, including areas >10 cm deep. Sediment particle
size analysis suggested that sediment in Malibu was composed of more clay and silt than PV sediment,
which was mostly composed of sand. The smaller grain size in clay and silt are more easily transported
and re-suspended into the water column. The clay and silt content also suggest a terrestrial influence
in Malibu, which was supported by a higher content of organic matter in Malibu sediment. The amount
and stability of suitable substrate and the sediment type appeared to have the largest influence on kelp
distribution and abundance in Malibu and may help explain the patterns that have been observed over
the past 20 years.

42 SOIL MICROBIAL ACTIVITY AND MYCORRHIZAL ASSOCIATIONS IN A SOUTHERN
CALIFORNIAN SALT MARSH

Matthew W. Vandersande and Dr. Richard K Ambrose Environmental Science and Engineering
Program, UCLA

Traditionally, wetland restoration projects have focused on restoring the natural vegetation and
hydrology of the ecosystem. However, often overlooked are the subsurface soil components of the

28 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

system that are crucial to nutrient cycling, as well as the degradation of toxic compounds. In this
project, we evaluated the spatial and temporal dynamics of the soil microbial community in the natural
salt marsh and restored sites at Mugu Lagoon, Ventura County, USA.

We used two different indices, one specific and one general, to assess the overall soil microbial
community. The first method used was soil respiration—the rate of CO, efflux from the soil. While
soil respiration is a rather general indicator, it provides a valuable overall measurement of the soil’s
biological activity. Measurements of soil respiration were conducted using a closed, dynamic-system
infrared gas analyzer. The second method used to assess the microbial community was mycorrhizal
associations. The symbiotic infection of plants by arbuscular mycorrhiza has been shown to commonly
occur in terrestrial plants but is less well understood in aquatic environments. By understanding the
distribution of, and factors affecting mycorrhizal associations, restoration efforts can potentially facil-
itate the symbiosis, and promote a more active soil microbial community.

43 OCCURRENCE OF GYRODACTYLUS PERFORATUS (MONOGENEA) ON ITS FISH
HOST CLEVELANDIA IOS (GOBIIDAE) FROM BODEGA BAY AND TOMALES BAY,
CALIFORNIA

M. P. Walberg, E. Diamant, and K. Wong. University of California, Los Angeles, Department
of Organismic Biology, Ecology, and Evolution, Los Angeles, CA, 90095

The monogenetic trematode Gyrodactylus perforatus was previously reported to infect populations
of the arrow goby, Clevelandia ios, from Bodega Bay, California. Clevelandia ios were sampled from
Bodega Bay and nearby Tomales Bay using two different collection methods and examined for G.
perforatus. Procedures for removal, processing and examination were previously developed for mi-
croscopic monogenes in other fish hosts and these processes were adapted for this study as necessary.
Gyrodactylus perforatus was found on hosts in Tomales Bay, thus extending its range beyond its type
locality, Bodega Bay. Parasitism by G. perforatus on C. ios was statistically significant between the
samples and higher in Bodega Bay.

44 MANAGEMENT OF THE CALIFORNIA LEAST TERN BREEDING POPULATION

Kathy Keane, Keane Biological Consulting, 5546 Parkcrest Street, Long Beach CA 90808 USA,
keanebio @cs.com

The California Least Tern (Sterna antillarum browni) breeds from April through August at nesting
areas along the coast from the San Francisco Bay, California to lower Baja California, Mexico. Prior
to its listing as endangered under both the federal and California Endangered Species Act in the early
1970’s, the progressive conversion of suitable nesting habitat to human uses had resulted in a severe
reduction in both nesting sites and numbers of nesting pairs. Thereafter, the number of nesting pairs
in California escalated from an estimated 664 in 1976 to over 4,000 in 2001, and up to 38 nesting
sites are now used, up from 23 in 1976, when statewide censuses were initiated. However, over 80%
of the nesting population is concentrated in 10 sites. In addition, poor production years such as 1999
still threaten the population, as does predation by a variety of both native and non-native predators.
However, predator management at some sites seriously threatens other uncommon native species. Thus,
although continued predator management will be required to ensure the health of the Least Tern
breeding population, the upcoming revised Recovery Plan must include a comprehensive and enforce-
able predator management plan that considers the needs of predators that have a relatively minor effect
on Least Tern reproductive success.

45 CONSERVATION OF THE ENDANGERED SOUTHERN CALIFORNIA STEELHEAD IN
THE VENTURA RIVER: AN UPDATE ON THE PROPOSED REMOVAL OF MATILIJJA
DAM

Sabrina L. Drill. University of California Cooperative Extension, 2 Coral Circle, Monterey Park,
CA 91755

In 1997, the National Marine Fisheries Service added the Southern California Steelhead (Oncor-
hynchus mykiss) to the endangered species list. It is estimated that annual steelhead runs in southern

ABSTRACTS 29

California streams declined from 55,000 to less than 500 returning adults in the past half century.
Historic runs in the Ventura River, considered a source population for smaller coastal streams, are
estimated at over 5000 fish. Barriers to passage are one of the leading causes of steelhead decline in
southern California. In the Ventura River system, Matilija Dam is the largest fish passage barrier,
blocking access to the majority of historic spawning and rearing habitat in Matilija Creek. The dam
was constructed in 1947 to control flooding of the Ventura River, and provide storage for a municipal
water supply. However, given the highly erodable geology of Matilija Canyon, the reservoir quickly
filled with silt, estimated today at around 6 million cubic yards of material. Currently, the dam provides
no flood control, and very little storage. Removal of the dam would double the amount of spawning
and rearing habitat in the Ventura River system. In 1998 the Ventura County Board of Supervisors
committed to dam removal. The Matilija Dam Ecosystem Restoration Feasibility Study, a joint project
of the U.S. Army Corps of Engineers and the Ventura County Flood Control District, is currently
underway. Preliminary results of the study and the development of a habitat evaluation protocol for
assessing the impact of dam removal will be discussed.

46 CONSERVATION DILEMMAS INVOLVING ENDANGERED SPECIES IN THREE
SOUTHERN CALIFORNIA HABITATS: SAN MIGUEL ISLAND, BOLSA CHICA WET-
LANDS AND RIPARIAN WOODLANDS

Daniel A. Guthrie, Claremont McKenna Scripps and Piteer Colleges, Claremont, Ca. 91711

Protection of endangered species often leads to policies that may cause problems for other species,
or require habitat manipulation. Three examples of this are presented. Reintroduction of bald eagles
to the northern Channel Islands may harm alcids. Restoration of the Bolsa Chica wetlands for light-
footed clapper rails will harm Belding’s savannah sparrow, another endangered species. Finally, arti-
ficial destruction of flood protected riparian woodlands, a policy generally not favored, may be nec-
essary to maintain habitat for least Bell’s vireo.

47 THE IMPORTANCE OF MANAGEMENT OF THE NATIVE PARASITIC PLANT CUS-
CUTA SALINA IN SOUTHERN CALIFORNIA SALT MARSH HABITAT

Christina Simokat, Department of Biology, California State University San Marcos, San Marcos,
CA 92096

The disappearing coastal salt marsh habitat of California has a small number of native, specialized
plant species, which include a native plant parasite, alkali dodder (Cuscuta salina). Though little is
known about the ecology of parasitic plants, there is evidence of coevolutionary interaction between
C. salina and plants in the Pickleweed (Salicornia virginica) series which may influence the boundaries
of plant communities and their diversity. Historically, Salicornia has been known for its agricultural
uses and it is the nesting area for endangered bird species. Research has also begun into the phar-
macological uses of Cuscuta. Both for the ecological and economic benefits, it may be preferable to
manage rather than eradicate this parasitic plant in its native habitat.

48 AVIAN POPULATIONS IN DIMINISHING OPEN SPACE: A SURVEY OF THE BIRDS OF
SIGNAL HILL, CA

V. Anne Short, Department of Biological Sciences, California State University, Long Beach,
California

It is the nature of environments to change. Entire epochs of our earth’s history are marked by
massive, and sometimes devastating, environmental changes. Modern society often brings about rapid
change, and the urbanization of our landscape has caused sometimes-drastic changes in the make-up
of avian populations. Even small pockets of open space and natural plant communities can harbor and
maintain a high diversity of bird species. This study was designed to monitor and record the changes
in the open space remaining on Signal Hill, California. Since September of 2000, biweekly avian
surveys have been conducted at prescribed points, with opportunistic observations made in between.
I found 23 permanent resident species, 5 winter residents and 28 transient species, of which 40% use

30 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

the area as they pass through on migration or as temporary hunting grounds. The winter resident
Yellow-rumped Warblers are particularly abundant, comprising up to 75% of the entire avian popu-
lation during the winter months. Excluding transients, populations sizes of most of the species re-
mained largely the same during the study period. Loggerhead Shrikes (Lanius ludovicianus) and Say’s
Phoebes (Sayornis saya), however, have both shown substantial decreases during the study, and their
extirpation from the area may be imminent. This is concurrent with the ongoing transition of open
habitat to housing tracts. These data will serve as a base line for further studies as urbanization of the
area continues.

49 ARE SOUTHERN CALIFORNIA’S CHANGING COASTAL WATERS AND NEARSHORE
BIOLOGICAL COMMUNITIES BECOMING MORE SUSCEPTIBLE TO INVASION BY EX-
OTIC SEAWEEDS?

S. N. Murray. Department of Biological Science, California State University, Fullerton, CA
92834-6850

Evidence suggests that invasive species may impose increasing threats to biodiversity because of
global change. For example, increased sea temperatures can alter the distributions of marine species,
and make northern regions more susceptible to invasions by species native to lower latitudes. Southern
California’s waters experienced a two-decadal warming period beginning in the mid-1970s, and re-
cently appear to have entered a cooler thermal regime. These urban coastal ecosystems also were
exposed to increasing levels of urban run-off and other forms of anthropogenic disturbance. During
this period changes have occurred in the composition of coastal seaweed communities. Until recently,
few introductions of exotic seaweeds have been reported in Southern California. Perhaps, seaweed
invaders escaped detection because of their small size or identification difficulties. During the last five
years, however, three conspicuous seaweeds invaded Southern California waters. Undaria pinnatifida,
a kelp native to the western Pacific was recently reported in Los Angeles, Port Hueneme, Santa
Barbara, and Monterey harbors, and off Santa Catalina Island. Caulacanthus ustulatus, a small, red
alga, has been found in rocky intertidal habitats along the Orange County coast where it grows as a
low turf. Lastly, Caulerpa taxifolia, first noted as an invader in the Mediterranean Sea, was found in
Agua Hedionda Lagoon in San Diego County and Huntington Harbour in Orange County. The ap-
pearance of these seaweeds may be related to changing ocean conditions, but nevertheless represents
a warning that other exotic species might be capable of establishing populations in changing Southern
California waters.

50 WHAT IS NONINDIGENOUS AND IS IT ALL BAD?

J. N. Baskin and T. R. Haglund, California State Polytechnic University Pomona, Biological
Sciences Department, Pomona, CA 91768

The present symposium and numerous publications document the negative ecological impacts and
economic costs associated with the numerous nonindigenous forms of many taxa that have been
introduced around the world. The normally accepted definition of nonindigenous is anything that is
not found naturally in a particular geographic location. We discuss this definition critically, using a
diverse array of examples. Nonindigenous forms run the gamut from genes to species, involving
intergradation, introgression and competitive replacement. Introduction scales for aquatic forms range
from intrabasin to intercontinental. Origins may be ‘“‘natural’’ or anthropogenic including both inten-
tionally and nonintentionally translocated forms. Time frames range from prehistoric to recent. We
speculate briefly on some questions of value and ethics, including our view of the reasons we consider
nonindigenous forms negatively. We conclude that all biological entities introduced into an area by
man’s activities should be considered nonindigenous, but that all are not equal, either ethically or
practically. When considered holistically the presence of some nonindigenous forms may be beneficial.

il THE MARINE INVADERS OF CALIFORNIA: LESSONS FROM SAN FRANCISCO AND
SAN DIEGO

Jeffrey A. Crooks. Southwest Wetlands Interpretive Association, Tijuana River National Estu-
arine Research Reserve, Imperial Beach, CA 91933

invasions of exotic species continue to alter the structure and functioning of ecosystems worldwide,
ind the coastal embayments of California now harbor a wide variety of introduced plants and animals.

ABSTRACTS 31

While San Francisco Bay has a well-deserved reputation as one of the most invaded ecosystems in
the world, the coastal systems of San Diego also have many invaders. Although any comparisons
across these systems must be viewed as preliminary because of uneven sampling effort, examination
of invaders in these two systems reveals some interesting patterns. These include an increasing rate
of appearance of exotics in recent decades and unique suites of invaders that highlight differences
between the two regions. Detailed examination of two California invaders, the salt-marsh destroying
isopod Sphaeroma quoyanum and the mat-forming mussel Musculista senhousia highlights two broad
issues that merit increased attention in invasion biology: |) the existence of prolonged lags between
the initial invasion and subsequent population explosion of exotics, and 2) the ability of exotics to
profoundly affect invaded ecosystems by altering the physical nature of habitats through ecosystem
engineering.

52 US. RESPONSE TO POTENTIAL ECOLOGICAL THREAT TO SOUTHERN CALIFOR-
NIA ECOSYSTEMS BY THE INTRODUCED MARINE CHLOROPHYTE CAULERPA
TAXIFOLIA

R.A. Woodfield and K.W. Merkel, Merkel & Associates, Inc., 5434 Ruffin Rd., San Diego, CA,
92123

In 2000, the invasive strain of the seeweed Caulerpa taxifolia was documented at two southern
California sites. A clone of this strain inadvertently introduced into the Mediterranean in the 1980’s
is reported to currently blanket over 13,000h of bottom, often to the exclusion of native seaweeds,
seagrasses, reefs, and other communities. Upon discovery of this species in the U.S., regulators had
to quickly assess the potential threat of this introduction and develop an appropriate response. Despite
conflicting evidence on the ecological impact of this strain, the majority of reports from the Mediter-
ranean suggested that delay could be fatal to a successful eradication effort, a conclusion that had
already prompted the addition of Caulerpa taxifolia to the Federal weed lists and the development of
a national response plan prior to its discovery. Scientists and government agents concluded that due
to Caulerpa’s rapid growth potential, ecological plasticity, and toxic qualities, these infestations had
to be treated immediately. No long term monitoring was conducted prior to initiation of eradication
efforts in California, however review of distribution maps of eelgrass before the infestation seems to
confirm its reported tendency to displace native habitats. Due to American hesitancy regarding field
research on extant Caulerpa, future empirical assessments of its ecological impacts will likely be
designed as collaborations among affected countries, such as Australia, France, Italy, where eradication
is not being pursued. Likely impacts of Caulerpa on our ecosystems include competition with native
species, interruption of floral and faunal recruitment, and general alteration of existing habitats.

53 EXOTIC AQUATIC TURTLES ON THE WEST COAST: CONSIDERATIONS AND IM-
PLICATIONS

Mark R. Jennings(1), Dan C. Holland(2) and Robert H. Goodman, Jr.(3). (1) Rana Resources,
39913 Sharon Avenue, Davis, CA 95616 (2) 334A East Fallbrook Street, Fallbrook, CA 92028
(3) Citrus Community College, 1000 W. Foothill Blvd., Glendora, CA 91741

In the states of California, Oregon, and Washington, at least 27 species of exotic (non-native) aquatic
or semi-aquatic turtles from 20 genera and 5 different families have been recovered or reliably reported
from within the range of 3 native aquatic turtle species: the western pond turtle (Clemmys marmorata),
the western painted turtle (Chrysemys picta), and the Sonoran mud turtle (Kinosternon sonoriense).
Many of these turtles originated as pets or as potential food sources for human consumption. At least
4 of these exotic species are known to be reproductively established in one or more locations in the
wild, and another 2—3 species have a high potential of becoming reproductively established as well.
Concerns regarding the establishment of exotic turtles in the wild include potential negative impacts
to native turtles and other wildlife species through the transmission of pathogens and/or parasites,
direct and indirect competition, and predation. We discuss the exotic turtles most liable to cause harm
to the native turtle fauna and possible measures to control or reduce the spread of exotics.

32 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

54 EXOTIC FISH SPECIES AND THEIR IMPACTS ON SMALL COASTAL LAGOONS IN
SOUTHERN CALIFORNIA

Camm C. Swift! and Dan C. Holland’. Emeritus, Section of Fishes, Natural History Museum
of Los Angeles County, Los Angeles, CA 91007; and 334A East Falbrook, Fallbrook, CA
92028

Both freshwater and estuarine exotic (non-native) fish species impact small souther California coast-
al lagoons. In the seven small lagoons (0.5—50 hectares) on Marine Corps Base Camp Pendleton, the
larger of these lagoons are more impacted by exotics because they have larger drainages upstream
that support freshwater exotic, primarily mosquitofish, sunfishes and black basses, and catfishes. The
smaller of these lagoons have fewer upstream sources and more seasonal drying upstream that impede
downstream movement by exotics. Marine invasion has been documented for two exotic species,
yellowfin goby and striped bass, both particularly facilitated by the latest El Nino-La Nina cycle. The
El Nino coincided with a large increase in yellowfin goby recruitment in the Santa Margarita estuary
and the only occurrence of this goby in several smaller systems. Increased numbers of striped bass
arrived later during the following La Nina. There appears to be a strong negative correlation of
mosquitofish with tidewater goby success at some sites. The federally endangered tidewater goby
appears to do best in the smallest sites without mosquitofish. The striped bass were few in number
and apparently had little impact and the increase of yellowfin gobies was relatively short lived, as the
influx of other southern native forms, that their effect was relatively fleeting.

55 INVADER IN THE OPEN SEA! THE NEW ZEALAND MARINE SW4AIL PHILINE AU-
RIFORMIS IN SOUTHERN CALIFORNIA COASTAL WATERS

D. B. Cadien, Marine Biology Lab, County Sanitation Districts of Los Angeles County, 24501
S. Figueroa St., Carson, CA, 90745

Sometime in late 1994 Philine auriformis, a clam predator from New Zealand, first appeared in
Southern California Bight (SCB) coastal waters. This is one of a few documented introductions to
shelf communities; most exotic species are reported from bays, harbors, or the intertidal zone. P.
auriformis was first collected in California from San Francisco Bay in 1993, and spread within a year
to Bodega Bay to the north. By the spring of 1995 specimens were abundant on the shelf off Los
Angeles and of very large size. Population density increased in 1995 and 1996 only to decline in
1997 and 1998. Off San Diego the population cycle was similar but less pronounced. By 1998 the
species was established at reduced density in much of the Bight based on regional monitoring. Such
coastal invasions may pass unnoticed in transitional areas such as the SCB because of high natural
variability. Predator/prey interactions with other animals are discussed in relation to the invasion
history.

56 INTERACTION BETWEEN NATIVE FISH, HABITAT, AND EXOTIC FISH SPECIES IN
THE MIDDLE SANTA ANA RIVER, SOUTHERN CALIFORNIA

Camm C. Swift, Emeritus, Section of Fishes, Natural History Museum of Los Angeles County,
Mailing address: 346 West Le Roy Avenue, Arcadia, CA 91007

Two native fish species, Santa Ana sucker and arroyo chub, occur in about 55 km of the middle
Santa Ana River. The upstream 9 km with higher gradient, rocky and gravelly, substrate, and artificially
fluctuating flow supports populations of each species. The stream adapted sucker and chub are main-
taining themselves in artificially fluctuating flows that probably limit most of the egg-laying exotics
fishes. Two exotics, the live-bearing mosquitofish and mouth-brooding tilapia can survive. The next
river reach down to Prado Dam (27 km) with lower gradient, overwhelmingly shifting sand substrate,
increased turbidity, and dampened fluctuation in flow, lacks arroyo chubs. Juvenile suckers occur in
small numbers in spring, summer and fall, after the spring spawning season upstream and adult suckers
are rare. Exotics like mosquitofish, sunfishes and largemouth bass, carp, and bullhead catfishes are
common. The lowermost reach below Prado Dam (19 km) with higher flows, more turbidity, and a
mixture of substrates, has only a few adult suckers and no .arroyo chubs. Exotics are more common
including channel catfishes. Arroyo chubs, ecologically more adapted to the lower gradients, are absent
‘ownstsream apparently because of the high number of predatory exotics. Sucker reproduction is

ABSTRACTS

oS)
eS)

lacking downstream or not successful. During the El Nino spring of 1998 juvenile suckers were
common below Prado Dam indicating possible reproduction at that time. Channel catfishes were rare.
In later years channel catfishes greatly increased in numbers and both adult and small suckers were
very rare. High flows appear to have improved conditions for suckers in 1998.

57 MONITORING OF NEARSHORE MARINE HABITATS FOLLOWING BEACH REPLEN-
ISHMENT ACTIVITIES

L. Honma! and R. Rundle?. 'AMEC Earth & Environmental, 5510 Morehouse Dr., San Diego,
CA 92121. ?San Diego Association of Governments, 401 B Street Suite 800, San Diego, CA
92101

The San Diego Regional Beach Sand Project dredged just over two million cubic yards of sand
from four offshore borrow sites and replenished 12 beaches along the coast of San Diego County
from Oceanside to Imperial Beach. Surveys conducted during the environmental documentation pro-
cess identified nearshore rocky reefs in the vicinity of several of the proposed receiver sites. Concern
from resource agencies and commercial fishermen regarding the potential for the sand placed on the
beaches to impact these reefs promulgated monitoring of rocky intertidal, shallow subtidal, and kelp
forest habitats in the vicinity of select receiver sites. The purposes of the monitoring are to determine
any significant effects to sensitive marine resources, to understand the long-term ramifications of the
project, and to aid in the design of future projects. Determination of monitoring locations and sample
design will be discussed and preliminary data presented.

58 ANALYSIS OF AERIAL PHOTOGRAPHS TO DETERMINE THE EFFECTS OF THE DIA-
BLO CANYON POWER PLANT THERMAL DISCHARGE ON KELP CANOPIES

Scott Kimura and James Strampe (TENERA Environmental, San Luis Obispo, CA 93401)

We analyzed aerial photographs taken in summer/fall of 1969-91 and 1997—98 to determine the
effects of the Diablo Canyon Power Plant thermal discharge on the surface canopies of giant kelp,
Macrocystis, and bull kelp, Nereocystis. During each survey, color IR transparencies (9@ * 9@) were
taken sequentially (30—60% overlap) along a 14 km section of coastline. The images were digitized
(1 m resolution) and the color bands representing kelp canopies were extracted using Adobe Photosh-
op-. GIS (ArcView-) was then used to geo-reference the kelp images to a projected USGS model of
the coastline. Because bull kelp and giant kelp often appeared similar in the photographs, we also
conducted ground-truth surveys to verify the locations of the two species. Kelp cover for various
segments of the coastline were calculated using GIS, and the data were analyzed using a before-after-
control-impact statistical design to test for changes in surface canopy cover in high and low impact
areas, relative to controls. Bull kelp declined significantly in Diablo Cove after power plant start-up,
and giant kelp gradually increased in the same habitats. Consequently, the main discharge effect was
a shift in species composition, but not an overall change in summer/fall canopy cover. In contrast,
total kelp cover significantly increased in the low impact area adjacent to Diablo Cove, mainly from
increases in giant kelp. The photographs also provide a valuable long-term record of natural variation
in kelp canopies related, in part, to regional influences from El Nifio events and sea otter predation
on herbivore populations.

59 INTERPRETING HISTORICAL RECORDS OF SIZES OF KELP BEDS

W. J. North. W.M. Keck Engineering Laboratories, California Institute of Technology, Pasadena,
CA, 91125

Many of the 24 kelp (Macrocystis) beds of San Diego and Orange Counties appear to have been
nutrient-limited during most of the past two decades, based on canopy histories as determined by
aerial photography. Frequent occurrences of moderate-to-large el nino events since 1982 have un-
doubtedly been influential in maintaining a general nutritional deficiency in the local coastal waters.
1989-90 were exceptional years that witnessed a powerful la nina, associated with large expansions
by most of these beds. A moderate la nina episode following the large 1997-98 El Nino was also
beneficial for Macrocystis canopies, but not to the degree that occurred during 1989—90.

34 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

60 UPDATE ON THE SAN CLEMENTE ARTIFICIAL REEF PROGRAM

Robert Grove', Steve Schroeter”, Dan Reed’, Todd Anderson? (‘Environmental Affairs, Southern
California Edison; *Marine Science Institute, UCSB; *Department of Biology, San Diego State
University)

The second year of monitoring the 22.4-acre San Clemente Kelp Experimental Artificial Reef
(SCAR) has been completed. This study is directed by the California Coastal Commission, conducted
mainly by the Marine Science Institute of the University of California Santa Barbara and San Diego
State University, and funded by Southern California Edison. Two materials, broken concrete and quarry
rock, and three bottom coverage densities, 17%, 34%, or 67%, are being tested to determine the best
design for the build-out of this kelp mitigation reef to 150 acres. The experimental reef was built in
September 1999. Results shows that the fifty six 40 m by 40 m concrete and quarry rock low-relief
modules: 1) remain physically stable; 2) are maintaining kelp; and 3) have populations of fish, algae,
and invertebrates that are comparable in density to nearby natural reefs, but differ in species compo-
sition. This program is also studying the potential effect of SCAR on the adjacent City and State
Beaches. In the project’s environmental review phase, concern was raised about the potential of reef
material washing up on the beach, and kelp wrack increasing substantially. Routine observations of
the San Clemente beaches show no artificial reef material, either quarry rock or concrete, has washed
onto the beach, nor has there been evidence that kelp wrack from the artificial reef makes any sig-
nificant contribution to the limited amount of seaweed wrack that has routinely appeared on the beach.
It is likely that episodic large wave events drive the significant beach accumulation of kelp wrack.
Nearshore conditions over the two years and since the reef was built have been somewhat tranquil,
that is, without major storms. The program scientists are awaiting significant storms or an El Nino
event to provide an effective test of the likelihood that the artificial reef will contribute significantly
to wash-up of wrack or artificial reef material on local beaches and/or have other measurable or
possibly catastrophic influences on SCAR.

61 REEF—A VOLUNTEER FISH MONITORING PROGRAM IN CALIFORNIA

C.V. Pattengill-Semmens. Reef Environmental Education Foundation, P.O. Box 246, Key Largo,
FL 33037, 206-529-1240, christy @reef.org

The REEF Fish Survey Project is a volunteer fish-monitoring program developed by the Reef
Environmental Education Foundation (REEF). REEF volunteers collect marine fish distribution and
abundance data using a standardized visual method during regular Scuba and skin diving activities.
Survey data are recorded on preprinted data sheets that are returned to REEF and optically digitized.
These data are housed in a database that is publicly accessible on REEF’s Website (http://
www.reef.org). Since its inception in 1993 the REEF program has generated over 35,000 surveys in
the Caribbean region. In 1997 REEF expanded to the west coast of the United States and Canada,
and to date, approximately 1,500 surveys have been conducted in California. REEF’s standardized
census method provides a consistency in data collection applied over a wide geographic range. The
database establishes baseline data, provides a taxonomic inventory, and can be used to develop species
distribution maps and examine species and community trends. Analyses of the California REEF dataset
will be presented, including a species distribution and diversity atlas.

62 LONG-TERM CHANGES IN FISH POPULATIONS IN THE VICINITY OF DIABLO CAN-
YON POWER PLANT, CENTRAL CALIFORNIA

J.C. Carroll and J.R. Steinbeck. Tenera Environmental, 225 Prado Rd., Suite D, San Luis
Obispo, CA, 93401

The Diablo Canyon Power Plant is a 2200 MW nuclear facility located midway along a 20 km (12
mi) reach of rocky coastline in central California. We studied the effects of heated seawater from the
cooling water discharge on fish populations in Diablo Cove and surrounding areas by conducting
visual censuses along permanent subtidal transects. Quarterly surveys began in 1976, nine years before
plant start-up in 1985, and have continued through 2002. Over 80 fish species representing 30 families
have been counted in 115 surveys. We used a BACI-type analysis to measure discharge effects on

common fish species by comparing temporal changes in their abundances between Diablo Cove

ABSTRACTS 35

and a nearby control area. Approximately 35% of the 37 taxa tested for power plant impacts increased
after plant start-up, 20% decreased, and 15% were unchanged. Counts on the remaining 30% were
too variable to yield conclusive test results. Bat rays, leopard sharks, white seabass, pile perch, se-
Noritas, and kelp bass were among the species that were attracted in greater numbers to the shallow
areas of Diablo Cove. Species with cool-temperate affinities, such as painted greenlings, kelp green-
lings, and cabezon, were among the species that declined. The longevity of this study has enabled us
to track natural changes in local fish populations related to large scale phenomena such as El Nifio
warming events, and also describe subtle long-term changes that continue to occur in Diablo Cove as
a result of the thermal discharge.

63 DECLINES IN ROCKY REEF FISH POPULATIONS: HAVE DIFFERENT SPECIES RE-
SPONDED SIMILARLY TO ENVIRONMENTAL CHANGE?

A. Brooks, R. Schmitt, & S. Holbrook. Marine Science Institute, University of California Santa
Barbara, Santa Barbara, California, 93106 USA

There is compelling evidence that the abundances of many coastal species off southern California
have undergone dramatic declines over the past two decades concurrent with declines in productivity.
The decline in productivity represents a natural, large-scale perturbation and provides an opportunity
to understand whether and how various components of coastal ecosystems respond. We conducted
time-series analyses on long-term studies of non-exploited fish populations throughout the Southern
California Bight to describe their temporal trends and explore the timing and magnitude of change.
The species examined were classified as to trophic level, mode of reproduction and longevity, and
habitat. In general, the magnitude of decline was similar for all species, regardless of classification.
Trends were similar at all locations examined within the Bight, suggesting regional declines in abun-
dances rather than redistribution of individuals. These patterns are consistent with the explanation that
a regional decline in productivity is responsible for regional decline in fish stocks.

64 LONGTERM DECLINE OF ICHTHYOPLANKTON ABUNDANCE IN SANTA MONICA
BAY

D.J. Pondella, Il. Vantuna Research Group, Occidental College, Department of Biology, Los
Angeles, CA, 90041

From 1974 to the present, the Vantuna Research Group at Occidental College has monitored the
ichthyoplankton of King Harbor, Redondo Beach. Ichthyoplankton tows have been conducted monthly
during this period. This database enables us to infer the abundance of over 100 species of larval fishes
during this period. Nearly every species has declined during this period. This decline mirrors a decline
in plankton volume and is similar to trends observed for adult fishes. While this report is on the fish
larvae of the nearshore environment, these declines are indicative of regional trends for the Southern
California Bight.

65 REGIME SHIFTS IN CALIFORNIA CURRENT ZOOPLANKTON ASSEMBLAGES

M.D. Ohman! and B.E. Lavaniegos'’. 'Integrative Oceanography Division, Scripps Institution
of Oceanography, La Jolla, CA 92093-0218, and *CICESE, Ensenada, Mexico

The CalCOFI zooplankton time series extends from 1949 to present, providing an unprecedented
opportunity to assess long-term variability in North Pacific pelagic assemblages and the links of such
variations to climatic forcing. Although El Nino-scale perturbations to pelagic assemblages have long
been recognized, here we present evidence that lower frequency, multi-decadal scale variations occur.
In addition to significant changes in 1977, corresponding to a widely recognized basin-scale Regime
Shift, appreciable changes in absolute and relative abundance of various zooplankton taxa occurred
in 1999. These latter changes have persisted much longer than is typical of La Nina, posing the
question whether we have again entered an altered climatic regime in the NE Pacific. The relationship
of these zooplankton shifts to variations in the Pacific Decadal Oscillation will also be discussed.

36 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

66 MONITORING SUBTIDAL COMMUNITY CHANGES AT SURVEY ROCK, ANACAPA IS-
LAND: FORTY YEARS AND STILL COUNTING

J. Engle', J. Altstatt?, R. Ambrose?, J. Carroll* and J.A. Coyer>. 'Marine Science Institute,
University of California, Santa Barbara, CA 93106; *Santa Barbara ChannelKeeper, 120 W.
Mission St., Santa Barbara, CA 93101; *Department of Environmental Engineering, University
of California, Los Angeles, CA 90024; *Tenera Environmental, San Luis Obispo, CA 93401;
*Dept. of Marine Biol., University of Groningen, The Netherlands

In the early 1960s, Neushul ef al. studied the distribution of organisms on the south side of East
Anacapa Island, CA. Their 3-year study mapped the occurrences of common macroinvertebrate and
kelp species from the lower limits of the intertidal down to a depth of 40 meters, recording dense
populations of Macrocystis pyrifera, Agarum fimbriatum and Pterygophora californica. From 1981 to
2001, the Tatman Foundation’s Channel Islands Research Program has returned annually to Neushul’s
site at Survey Rock to study the kelp bed and surrounding areas from 6 tol8 meters in depth. Per-
manent transects and photo-quadrats were established in order to monitor the density and distribution
of macroalgae, sea urchins, and other benthic invertebrates. Kelp and other macroalgae, once in great
abundance, have been largely absent at the site since 1986 due, in part, to a combination of severe
urchin overgrazing and El Nifio episodes. Even during La Nifia periods the macroalgae did not recover
as expected. Our experimental studies at Survey Rock have also helped explain some of the less-
obvious dynamics between urchins, macroalgae and sessile invertebrates. Since the early 1990s we
have documented some unexpected and unprecedented trends, including vast increases in the abun-
dance of the brittlestar Ophiothrix spiculata and related decreases in some sessile invertebrate species.
We report on these trends and other changes in community structure at Anacapa Island supported by
subtidal observations spanning a period of over 40 years.

67 THE NEARSHORE FISH ASSEMBLAGE OF THE SAN DIEGO/LA JOLLA ECOLOGICAL
RESERVE

Craig, M. T., P. A. Hastings, and P. K. Dayton. Scripps Institution of Oceanography, 9500
Gilman Dr. Mail Code 0208, La Jolla, CA 92093-0208

Marine reserves such as the San Diego-La Jolla Ecological Reserve (SDLJER) are quickly becoming
a primary tool in the management of coastal marine ecosystems in California. The San Diego-La Jolla
Ecological Reserve was proposed in 1961 and established 10 years later. It has remained in place
since that time and represents one of the few marine reserves in extreme southern California. Although
relatively small (approximately 500 acres, including 1.6 miles of shoreline), it includes a variety of
habitats such as a kelp forest, boulders of various sizes and steep canyon walls. Beginning in January,
2002, a repeatable, quantitative protocol was established to monitor conspicuous marine fishes within
the SDLJER as a means of comparing abundance and diversity with comparable habitats that are
currently not under protection. Preliminary data suggests that the SDJER may serve to protect fisheries
target species and maintain upper size classes, and has a more diverse fish assemblage than that
observed at unprotected reefs at nearby Pt. Loma.

68 REMOTE TRACKING OF GIANT SEA BASS (STEREOLEPIS GIGAS) USING AN
ACOUSTIC SENSORY ARRAY AROUND ANACAPA ISLAND

Michael L. Domeier. Pfleger Institute of Environmental Research, 901-B PIER View Way,
Oceanside, CA 92054

It is thought that giant sea bass form a spawning aggregation at Anacapa Island during summer
months. Attempts to observe and document this event using traditional underwater monitoring and
observation techniques have not been entirely successful. Difficult diving conditions and the mobility
of the species create a very challenging situation that required a non-traditional approach. New acoustic
telemetry technology allowed for a non-traditional means of gathering quantitative data. This project
was the first to put Vemco VR2 remote logging hydrophones in the field. These hydrophones were
set up in an array that completely encircles the island. This array allows for the nearly continuous
detection of acoustic tagged giant sea bass that remain in the vicinity of the island. The array has
allowed the collection of a dataset that provides information on habitat use, migration to and from

ABSTRACTS 37

the island as well as movements around the island. To date we have tagged 27 adult giant sea bass at
Anacapa Island and we are moving ahead with plans to expand the array to neighboring islands and
begin data collection on some additional species.

69 SEXUAL DICHROMATISM AND SPAWNING BEHAVIOR OF THE KELP BASS, PAR-
ALABRAX CLATHRATUS, FROM SANTA CATALINA ISLAND, CALIFORNIA

B.E. Erisman. Nearshore Marine Fish Research Program, Department of Biology, California
State University, Northridge, CA, 91330-8303

The kelp bass, Paralabrax clathratus, is a common nearshore reef fish of the Southern California
Bight, being abundant on both the mainland and the Channel Islands. Although the biology of kelp
bass has been well studied, aspects concerning its mating system and reproductive behavior have
received little attention. The purpose of the study is to describe several aspects of the mating system
including (1) seasonal sexual dichromatism, (2) spawning behavior, and (3) general mating strategies
of breeding adults. Behavioral observations while on SCUBA were conducted along with underwater
video to document and describe spawning behavior. Visual fish transects performed at two sites were
used to assess the seasonal frequency of sexual dichromatism in adults. Data from samples collected
via hook and line indicate that ripe males adopt a highly visible, orange snout coloration that is absent
in ripe females, juveniles, and unripe adults. A separate tank study will be described in which hormonal
injections were done to induce the coloration in adult males and validate it as a characteristic unique
to breeding males. Gonadosomatic indices calculated from ripe adults collected during peak breeding
season showed that adults may invest up to 12% of their body weight for gamete production, indicating
the species as a group-spawner. Spawning rushes have been observed on several occasions and have
consisted of 6—16 individuals. Spawning rushes have only been observed during twilight hours, al-
though data from collected specimens show that eggs may become hydrated throughout the day.

70 REPRODUCTIVE BEHAVIOR AND MATING SYSTEM OF THE TEMPERATE WRASSE,
HALICHOERES SEMICINCTUS

M.S. Adreani. Nearshore Marine Fish Research Program, Department of Biology, California
StateUniversity, Northridge, CA, 91330

The reproductive biology of the southern California labrid fishes has been studied extensively in
the past and has led to further study of their behavior and ecology. The reproductive behavior and
mating system of the rock wrasse (Halichoeres semicinctus) has been recorded and monitored in and
around Big Fisherman’s Cove, Santa Catalina Island, CA during April—October 2001. Three sites were
visited almost daily during June-August and observed twice monthly during the spring and fall. It
has been found that group spawning occurs with small (<20 cm), initial phase individuals with an
average of 10 individuals per spawn. It appears that large, terminal phase males hold territories and
participate in pair spawnings. Sex change in this species is rare (<5%) and a nearly 1:1 sex ratio has
been shown. Abundances of rock wrasse fluctuated at the three sites throughout the day indicating
that there was movement to and from spawning sites. All spawnings were seen between the hours of
800 and 1200, though aggressive, territorial behavior by terminal phase males was witnessed through-
out the day. The majority of spawning occurred on the downcurrent edges of the studied rocky reefs.

71 PUTATIVE FUNCTION OF TYROSINE D OF PHOTOSYSTEM I PROBED BY FLUORES-
CENCE AND OPTICAL ABSORBANCE SPECTROSCOPY

Jennifer H. Jones and Richard J. Debus. Department of Biochemistry, University of California,
Riverside, CA 92521

Photosystem II of the photosynthetic light reactions contains two redox-active tyrosine residues (Y,
and Y,). Tyrosine Y, shuttles electrons from the Mn cluster of the oxygen evolving complex to the
oxidized reaction center chlorophyll (P,g.°"), whereas Y; has no known function. Recent studies have
shown that the rate of electron transfer between Y, and P,g.°* at pH > 7.5 is as rapid as that between
Y7 and P,go'*. Such rapid electron transfer may have important mechanistic implications, one of which

38 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

is that Y, could increase the midpoint potential of P¢go't/Pggo. To test this possibility, the rate of charge
recombination in site-directed Synechocystis sp. PCC 6803 mutants having Y), replaced with phenyl-
alanine or glycine was measured. An acceleration of charge recombination between Q,~ and Y,’ was
measured in isolated PSII reaction centers with optical absorbance spectroscopy, a result consistent
with Y,, raising the midpoint potential of Peg’ */Pego. However, no acceleration of charge recombination
between Q,* and the partially oxidized Mn cluster was measured with fluorescence, a result consistent
with Y,, not affecting the midpoint potential of Pego'*/Pego. Additional experiments are underway to
solve this apparent paradox.

72 FIELD VALIDATION OF CHRONIC SUBLETHAL DREDGED MATERIAL LABORATO-
RY BIOASSAYS: PROGRAM DESIGN

M.A. Irwin, D.W. Moore. MEC Analytical Systems Inc. 2433 Impala Drive Carlsbad, CA
92008. TS. Bridges. Waterways Experiment Station, U.S. Army Corps of Engineers, 3909 Halls
Ferry Road, Vicksburg, MS, 39180

Federal regulations require the evaluation of potential dredged material for unacceptable environ-
mental effects prior to disposal. Standard evaluation of dredged material includes measuring acute
toxicity in benthic organisms over a ten day period in the laboratory, but chronic toxicity is not
routinely evaluated. In response to the need for chronic toxicity tests to measure long-term effects,
the USACE recently completed the development of two new chronic sublethal bioassays with the
marine polychaete worm Neanthes arenaceodentata and the estuarine amphipod Leptocheirus plu-
mulosus. In order to determine whether these tests accurately predict negative environmental impacts
upon the benthic community, a field validation program has been implemented. These two tests have
been used to evaluate different concentrations of a selected contaminated sediment and a clean ref-
erence sediment. These sediments have been placed in test containers and deployed in the field at a
selected test location. At specified intervals during the study the sediments in selected test containers
are retrieved and analyzed for infaunal community composition/re-colonization and toxicity. Results
of the chronic sublethal laboratory bioassays are compared to effects observed in situ to evaluate the
ability of the proposed tests to predict impacts on benthic infauna in the environment. In addition, the
chronic tests will be compared to the more standard 10-day acute toxicity tests to evaluate whether
acute or chronic sublethal tests provide a better prediction of observed benthic community responses.

73 FLOWER DENSITY EFFECTS ON POLLINATION OF ARTICHOKE THISTLE (CYNVARA
CARDUNCULUS L. ASTERACEAE)

L. Clarke and S. Banack, California State University, Fullerton, Department of Biological Sci-
ences, Fullerton, CA 92834-6850

Pollination studies of non-native plant species are few. Cynara cardunculus is a non-native, invasive
weed of lower elevation coastal regions in central and southern California. Due to the large size and
showy appearance of its inflorescence, C. cardunculus could have significant impacts on pollination
in natural communities; including, competition for pollinators and negative effects on reproductive
success of coflowering native species. I investigated how variation in the density of floral display
affects pollinator visitation rates and seed set in C. cardunculus. Specifically, pollinator visits and seed
set were compared between experimental plots of high and low density C. cardunculus flowers. Sol-
itary bees and honey bees accounted for the majority of visitors. Although there was significant
variation in visitation on a daily basis and throughout the study period, I found no significant difference
in pollinator visitation rates or seed set between dense and sparse plots. In addition, flower density
had no effect on the number of heads visited per plot. These results suggest that in this system
pollinators do not have a preference for patches with greater floral density.

74 COPPER TOLERANCE AND REMEDIATION POTENTIAL OF SALIX LASIOLEPIS: A
NATIVE CALIFORNIA WILLOW

C.M. Vadheim, K Williams, J. Roberts. Department of Biology, CSU Dominguez Hills, Carson
CA 90747

Urbanization, manufacturing and agricultural practices have increased copper in many S. California
rivers/streams, making it an important waterway contaminant. Increased copper levels may limit suc-

ABSTRACTS 39

cess of trees commonly used to remediate degraded wetlands/ riparian areas. We are therefore studying
copper tolerance of native CA willows including Salix lasiolepis (Arroyo willow). First we conducted
small pilot studies of the copper tolerance of asexually propagated S. /asiolepis cuttings grown in
soilless medium (10—12 weeks under greenhouse conditions). Copper content of the medium was
altered with dilute fertilizer solutions containing 0, 0.15, 0.3, 0.7 and 1.0 mg of added CuSO,AH,O/I.
At 10 weeks, cuttings treated with 0.3 and 0.7 mg/l copper sulfate grew more robustly than controls
(0.0) or those given 0.15 or 1.0 mg/l copper.

Group Total at 10 weeks (N=4/group)

Measure Control (0.0) 0.15 mg/l 0.3 mg/l 0.7 mg/I 1.0 mg/l
No. leaves 106 36 124 205 76
Leaf dry wt. OT 3Ng 0.43 ¢g 1.90 g 2.67 g 0.69 g
Shoot dry wt. 0.14 g 0.08 g 0.64 g 0.66 g 0.15 g
Root dry wt. 0.29 g 0.19 g O37 2 O7S-¢g 0.27 g

At 12 weeks, the group receiving 0.3 mg/I had higher, and that receiving 0.7 mg/l had lower, total
leaves and average leaf, shoot and root dry weights than the other groups. These very preliminary
results suggest Arroyo willow may be suitable for copper-contaminated riparian sites. We are currently
replicating results and extending studies to Salix gooddingii (Gooding’s willow) and S. laevigata (Red
willow).

75 WHAT DOES IT TAKE TO BE A HERBIVORE?—GUT STRUCTURE AND FUNCTION IN
THREE SPECIES OF NEW WORLD SILVERSIDE FISHES (TELOSTEI: ATHERINOPSI-
DAE) WITH DIFFERENT DIETS

M.H. Horn, A. Gawlicka, E.A. Logothetis, A.M. Jones, J.W. Cavanagh, D.P. German and C.T.
Freeman. Department of Biological Science, California State University, Fullerton, CA, 92834

We explored the possible diet-related specializations of the gut in stomachless fishes by comparing
the brush-border surface areas and enterocyte inclusions (in progress) of the gut epithelium and the
digestive enzyme profiles (in progress) in three closely related atherinopsid fishes using electron mi-
croscopy and biochemical assays. For these comparisons, we examined proximal, middle and distal
regions of the intestine of Atherinops affinis, from both kelp forest and estuarine habitats, and Ath-
erinopsis californiensis and Leuresthes tenuis, both from open coastal habitats. A. affinis is generally
a carnivore in kelp forests and a herbivore in at least some estuaries, whereas A. californiensis 1s
mainly carnivorous and L. tenuis strictly carnivorous. Previous work showed that relative gut length
in these species generally follows the expectation that carnivores have shorter guts than herbivores
and omnivores have guts of intermediate length. The herbivore (estuarine A. affinis) showed greater
overall microvillar surface area than the two more carnivorous species as well as the carnivorous
population of A. affinis. Thus, a degree of congruence exists between diet, gut length and absorptive
surface area, with the herbivore gut exposing a larger surface area to the ingested food material.

76 FEEDING PREFERENCES AND ASSIMILATION EFFICIENCIES IN THE HERBIVOROUS
MARINE SNAIL LITHOPOMA UNDOSUM (TURBINIDAE)

Erin Cox and Steve Murray, 800 N. State College, California State University, Fullerton, CA,
92834-6850

Many studies have examined factors that contribute to food choice in herbivorous marine inverte-
brates. However, few have considered relationships between preferences and the assimilation efficien-
cies of food items. The purpose of this research is to establish a preference hierarchy among seaweed
foods for the herbivorous marine snail Lithopoma undosum, and then to test the hypothesis that
preferred seaweeds are assimilated at higher efficiencies than less preferred seaweeds. Differential
consumption of seaweeds during three sets of two-choice experiments showed that L. undosum exhibits
clear feeding choices, preferring kelp species over nine other non-kelp macrophytes. Clear preferences
could not be detected among the kelp species tested. Following kelp, the fleshy red alga, Pterocladiella

40 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

capillacea was preferred over other species of macrophytes, followed by the calcified coralline Lith-
othrix aspergillium, which was preferred over two known chemically defended species and the sea-
grass, Phyllospadix torreyii. Assimilation efficiencies are now being quantified using an ash marker
method. Results to date indicate that L. undosum prefers kelps over all other seaweeds, but also exhibits
defined secondary preferences among less-preferred seaweed foods.

Me. WHENCE HAVE THEY COME, THE ABYSSAL GRENADIERS?

Raymond R. Wilson, Jr. and Phoebe Attia, California State University, Long Beach, Department
of Biological Sciences, Long Beach, CA 90840

Truly abyssal species of the grenadier genus Coryphaenoides are relatively few, represented in the
eastern North Pacific Ocean only by Coryphaenoides (Nematonurus) armatus variabilis (Giinther),
Coryphaenoides (Nematonurus) yaquinae Iwamoto and Stein, and Coryphaenoides (Chalinura) lep-
tolepis (Giinther). A few other, more poorly known species of subgenera Nematonurus, Chalinura, and
Lionurus, inhabit mostly. the fringes of the abyss elsewhere. A much higher diversity of Coryphae-
noides species is found worldwide on continental slopes between about 500 and 2,000 m. Phylogenetic
study of genus Coryphaenoides using allozymes suggested that the abyssal subgenera Nematonurus
and Chalinura were sister taxa and likely derived from slope species of Coryphaenoides. However, a
second study using DNA sequences from the!2s rRNA and COII mitochondrial genes suggested that
Coryphaenoides (Nematonurus) species might in fact be sister to all slope-dwelling Coryphaenoides
(Coryphaenoides) species, but the second study did not include the abyssal C. (Ch.) leptolepis. We
sequenced the relevant portion of the 12s rRNA gene for three more Coryphaenoides species, including
C.(Ch.) leptolepis, plus one Caelorinchus species, bringing the total for further analysis to ten ingroup
and four outgroup species. Maximum likelihood and maximum parsimony analyses of the 12s se-
quences suggested that the abyssal species of Coryphaenoides indeed form a sister taxon to the slope-
dwelling species of Coryphaenoides, and might represent a separate radiation.

78 PHYSIOLOGICAL RESPONSES TO VARIATIONS IN SALINITY AND NUTRIENTS BY
THE BLOOM-FORMING MACROALGA ENTEROMORPHA INTESTINALIS: IMPLI-
CATIONS FOR USE AS A BIOINDICATOR OF FRESHWATER AND NUTRIENT INFLUX
TO ESTUARINE AND COASTAL AREAS

R. A. Cohen and P. Fong. University of California, Department of Organismic Biology, Ecology
and Evolution, Los Angeles, CA, 90095-1606

Enteromorpha intestinalis is a bloom-forming species of macroalgae associated with eutrophication.
The objective of this study was to quantify the response of E. intestinalis to two factors that co-occur
with eutrophication, salinity reduction and nutrient enrichment. This alga is tolerant of a variety of
environmental conditions and responds to changes in salinity and nutrient supply on the cellular level.
We performed short-term laboratory experiments to examine the effects of salinity and nutrient supply
on tissue water content, potassium concentration, and nutrient content of E. intestinalis. These variables
were measured because tissue water content and potassium concentration are associated with osmo-
regulation, and tissue nutrient content indicates nutrient history of the algae. Results revealed that
tissue water content decreased significantly with increasing salinity, and this relationship was unaf-
fected by differing nutrient concentrations. Potassium concentration decreased as external salinity
decreased, demonstrating its role as an osmolyte. When salinity and nutrients were altered, the same
trend for tissue water and potassium emerged. However, the pattern was less pronounced in the pres-
ence of higher nutrient concentrations, suggesting that increased nutrient concentration in tissue may
also function in osmoregulation. Tissue nutrients increased with increased nutrient supply and this
pattern was unaffected by decreased salinity. The ability of this alga to rapidly take up available
nutrients for growth and short-term osmoregulation helps to explain the bloom potential of E. intes-
tinalis. Further, quantifying the physiological response to environmental change in the field will con-
tribute to our ability to detect changes in the level of eutrophication in coastal systems.

ABSTRACTS Al

79 THE USE OF AQUATIC INVERTEBRATES TO IDENTIFY ECOLOGICAL TRENDS IN
URBAN FRESHWATER STREAMS

W.H. Isham. MEC Analytical Systems, Inc. Carlsbad, CA, 92008

As urban development in Southern California progresses, watershed management issues become
increasingly important. Recognition of the effects of non-point source pollution and physical degra-
dation to freshwater streams and drainages can be difficult, and the inclusion of biocriteria in watershed
monitoring programs provides a direct measure of ecological response. The California Stream Bioas-
sessment Protocol is a standardized procedure utilizing biological and physical data to assess the effects
of water quality over time to a resident invertebrate population. This procedure was used to sample
22 stream monitoring sites in San Diego County in June, 2001. Three reference sites were sampled
for comparison. Benthic invertebrates were identified to standard taxonomic levels, and pre-established
taxa-based tolerance values were applied to calculate biological indices and provide an indication of
community tolerance to urban impacts.

80 COMPARISON OF FEEDING GUILD STRUCTURES OF INTERTIDAL FISHES FROM
CALIFORNIA AND CHILE: A MEASURE OF COMMUNITY CONVERGENCE

K. S. Boyle and M. H. Horn. Department of Biological Science, California State University,
Fullerton, Fullerton, CA 92834-6850

Spatially separated intertidal fish communities in similar environments may face the same selection
pressures. The intertidal fish community of central California is represented mainly by cottids and
zoarcoids, while the intertidal fishes of central Chile are mostly blennioids and no species are common
to both communities. We tested the hypothesis that convergent evolution of intertidal fishes from
central California and central Chile, both cool-temperate regions, has allowed for community conver-
gence by comparing the feeding guilds of Californian fishes with guilds of Chilean fishes. The diets
of the 14 most abundant intertidal fishes from central California waters were determined from fishes
collected at San Simeon, Pescadero Point, and Dillon Beach. A phenogram (UPGMA) of dietary
similarity was constructed and guild structure determined. The diets of Californian fishes were com-
pared objectively to the diets of 13 Chilean fish species (determined by Munoz and Ojeda 1997) by
creating a second phenogram. Similar resource guilds (e.g., omnivorous, microcarnivorous, Carnivo-
rous) were found in California and Chile despite the differing taxonomic affinities of their members.
An analysis of ecomorphological characters within feeding guild types from both regions is in progress
and is expected to provide further insight into convergent evolution in these two marine fish com-
munities.

81 DIGESTIVE ENZYME ACTIVITY IN HERBIVOROUS AND CARNIVOROUS PRICKLE-
BACK FISHES (STICHAEIDAE): ONTOGENETIC AND PHYLOGENETIC EFFECTS

D.P. German, M.H. Horn, and A. Gawlicka. Department of Biological Science, California State
University, Fullerton, CA 92834

We measured the activities of proteases and carbohydrases in four closely related species of pric-
klebacks to determine whether these fishes are genetically predisposed to digest a specific diet. Both
Cebidichthys violaceus and Xiphister mucosus shift to a more herbivorous diet as they grow (=45mm
SL), whereas X. atropurpureus and Anoplarchus purpurescens remain carnivores throughout life. Pro-
tease (pepsin, trypsin, aminopeptidase) and carbohydrase (amylase, maltase, isomaltase) activities of
small (30—40mm SL) carnivorous fish were compared with larger (60—75mm SL) fish raised on a
high-protein animal diet and with larger (60—75mm SL) wild-caught fish that had consumed a natural
diet. A. purpurescens, a member of a carnivorous clade, appears adapted to a high-protein diet because
it showed higher trypsin and aminopeptidase but lower amylase activity than the other fishes, and,
uniquely, increased trypsin activity when fed the high protein diet. The three other species, members
of an adjacent largely herbivorous clade, showed a significant increase in amylase activity with size,
even on the high-protein diet. The increase in amylase activity in C. violaceus and X. mucosus indicates
that the shift in diet and enzymatic activity may be genetically fixed, whereas in X. atropurpureu. the
increase may result from phylogenetic constraints.

42 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

82 REGULATION OF PROTEASE EXPRESSION IN THE CARNIVOROUS PLANT WEPEN-
THES ALATA

Jason Bae, California State University, Fullerton, Department of Biological Science, Fullerton,
CA 92834-3599

Many plants have evolved carnivory as a means of acquiring nitrogen. Unlike other means of
acquiring nitrogen, such as uptake by root or symbiosis with microbial species, carnivory requires
considerable investment of resources into production and maintenance of traps and hydrolases, diges-
tive enzymes. One means to maximize the benefits and minimize the costs of carnivory is the regu-
lation of hydrolases so that they are expressed only in presence of prey. In this study, the presence of
signal-based regulation of protease, protein-digesting enzyme, expression in a pitcher plant Nepenthes
alata was investigated using two different protease assays. Induction of protease expression upon
addition of nitrogenous compounds was observed in Nepenthes alata suggesting that this species
regulates its proteolytic activity based on presence of prey. The pH of the fluid in pitchers was also
found to be regulated by the presence of prey. In addition, a developmental regulation of proteolytic
activity was observed after opening of the pitchers in absence of prey. These data suggest that Ne-
penthes alata utilizes both signal-based and developmental regulation of proteolytic activity to increase
its chance of surviving by improving cost:benefit ratio of carnivory.

83 EFFECTS OF IN-UTERO COCAINE EXPOSURE ON THE DEVELOPING BRAIN

Amruta Kulkarny and Dr. Lynne Smith, Harbor UCLA REI Amruta Kulkarny and Dr. Lynne
Smith, Harbor UCLA REI 30427 Via Rivera, Rancho Palos Verdes, CA 90275

To understand the effects of maternal drug addiction on the child’s neurodevelopment and behavior,
two groups of children aged 3 to 13, one prenatally exposed to cocaine and the other unexposed
control, were tested last year in a pilot study at the Harbor UCLA Imaging Center. The database
contains individual Child Behavior Check List (CBCL) survey scores, as well as and volumes of
different brain regions and concentrations of metabolites from Magnetic Resonance Imaging and Spec-
troscopy (MRI and MRS). Based on statistical analysis, abnormality (or tendency toward it) with
prenatal exposure to cocaine is significant (p-value < 0.05) in most behavior categories, and partic-
ularly strong in aggressiveness, delinquency, and attention deficiency, all three of which seem to
correlate well with each other. Also, the exposure diminishes the volumes of midbrain (20%) and
cerebellum (10%) as statistically significant, but only when the volumes are scaled with the whole
brain volume. Further, the exposure is found to produce substantial and statistically significant increas-
es in the spread of data (standard deviations) in most of these variables, particularly in CBCL scores.
The major behavior and physiological effects appear consistent with current neuro-science literature
and suggest explanatory speculation about the prominent role of the dopamine neuro-circuitry.

84 NEUROANATOMIC OBSERVATIONS OF THE BRAIN IN AUTISM: NEUROIMAGING
STUDIES USING THE TECHNIQUE OF COREGISTRATION

C. K. Chen. Research and Education Institute, Harbor-UCLA Medical Center, Department of
Radiology, Torrance, CA 90502

Background and Purpose. Autism is a developmental disorder of brain function. Autistic patients
are characterized by their aloofness, obsession with repetition, and avoidance of social contact. Early
neuroimaging studies in autism failed to prove the significance that the cerebellum and limbic system
have on autistic behaviors. The purpose of the study is to investigate the relationship among the limbic
system, cerebellum, and autism using the technique of coregistration, a process whereby an exami-
nation scan of a patient is matched up with and corrected according to an atlas through mathematical
transformations. Methods. HMPAO-SPECT brain images were obtained through coregistering 3 groups
of autistic patients categorized by the seriousness of autistic traits a patient displays, and coregistering
| control group of the normal population. Values of uptake of each brain region of interest of the 3
autistic groups are then compared with those of the normal group to look for any abnormality. Results.
The cerebellum and the limbic system were found to be abnormal with respect to normal brains.
Furthermore, the cerebellum is associated with the lack of emotion displays characteristic of autistic
patients, and the limbic system is linked with autistic patients’ incapability to process new information

ABSTRACTS 43

and therefore an affinity for repetitive activities. Discussion. Using the process of coregistration, the
study proves that the limbic system and cerebellum are associated with autistic behaviors.

85 ON THE EFFECT OF LIGHT INTENSITY ON THE ELECTRICAL CONDUCTIVITY OF
FILAMENTOUS FUNGI

A.G. Craig. SCJAC Research Training Program

Molds, or filamentous fungi, consist of hyphae, long strings of cells. Some are septate, having walls
that separate one cell from the next. Others are coenocytic; they are continuous, elongated cell bodies
with multiple nuclei. Fungi feed by secreting digestive enzymes that hydrolyze their substrates, the
organic matter on which they grow, releasing nutrients, which they absorb through their cell walls.
When the mycelium, the body of a fungus, secretes hydrolytic enzymes, its electrical conductivity
should increase. I hypothesized that the electrical conductivity of the fungus would be higher when it
grew under intense illumination, because it would be adaptive for the fungus in its natural environment
to secrete greater quantities of digestive enzymes when more light fuels photosynthesis in the plants
on which the fungus grows. To test this hypothesis, I grew several cultures of Neurospora discretia
under different lighting conditions and tested the electrical resistance of a sample of approximately
equal size from each culture. I found no distinct correlation between the conductivity of the fungus
and the intensity of the light under which it grew.

86 INTERNUCLEOSOMAL DNA CLEAVAGE DETECTED IN MK-801 INDUCED RATS BUT
SHOW NO SIGN OF CASPASE-3 ACTIVATION IN CELL DEATH

R. Deniskin* and D. Fujikawa*t. *Experimental Neurology Laboratory, VA Greater Los An-
geles Healthcare System, Sepulveda Ambulatory Care Center and Nursing Home Unit, Sepul-
veda, CA 91343, U.S.A.; +Department of Neurology and Brain Research Institute, UCLA
School of Medicine, Los Angeles, CA 90095, U.S.A.

Neuronal apoptosis is produced in the neocortex by administration of the NMDA-receptor antagonist
MK-801 in neonatal rats, but whether programmed cell death (PCD) mechanisms are involved is not
known. This study was undertaken to determine if internucleosomal DNA cleavage (DNA laddering)
and caspase-dependent PCD occurs in apoptotic neurons. Control and MK-801 groups with 6 or 24
h survival underwent either (1) transcardiac brain perfusion-fixation with 4% paraformaldehyde for H
& E, TUNEL and CM1 antibody (to active caspase-3) staining, or (2) decapitation and rapid dissection
and homogenization of neocortex for DNA gel electrophoresis, Western blot analysis of active caspase-
3 and activity of endogenous caspase-3-like activity (DEVD-AFC cleavage assay). Thymuses of adult
rats given methamphetamine (MAP), to produce apoptotic thymocytes, or saline were used as controls
for caspase-3 activation. Following MAP treatment, apoptotic thymocytes showed TUNEL and CM1
antibody positivity, DNA laddering and a 25-fold increase of DEVD-AFC cleavage (1.13 + 0.11 vs.
0.05 + 0.01 units/:g protein, mean + SE, n = 3). TUNEL-positive neurons were found in the retros-
plenial (RS) and fronto-parietal cortices and ventromedial thalamic nucleus at 24 but not 6 h survival.
Some of the TUNEL-positive neurons also showed CMI antibody positivity. DNA laddering also
occurred in neocortex at 24 but not 6 h survival. However, DEVD-AFC cleavage activity was not
increased and the active caspase-3 (p17) fragment was not found by Western blot in the MK-801
treated rats. The data suggests that caspase-3 activation may occur in individual apoptotic neurons but
that widespread caspase-3 activation does not occur.

87 URBANIZATION OF COASTAL WATERS B CONCOCTING HORMONAL CHAOS

L.R. Patel and S.M. Bay, Southern California California Coastal Water Research Project
(SCCWRP), Westminster, CA 92683

Greater Los Angeles is a highly urbanized metropolis that uses an abundance of chemicals everyday.
As a result, it is quiet possible that there are increased concentrations of endocrine disruptive contam-
inants in the environment surrounding and part of Greater Los Angeles, where they can hinder and
alter healthy endocrine function in many organisms including but not limited to humans and wildlife.

44 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

In an effort to assess the endocrine disruptive potential of the environment around Greater Los

Angeles, a study was conducted involving the environmental sampling of 20 male Pleuronichtys
verticalis at five trawling sites (n = 4 at each site) in the coastal waters off of Greater Los Angeles,
and the use of 3 male Pleuronichtys verticalis as controls acquired from Dana Point, CA and accli-
mated in the lab. All 23 Pleuronichtys verticalis were blood sampled and assayed for vitellogenin, an
estrogen induced egg yolk protein not typically produced in males but inducible in the presence of
endocrine disruptive estrogenic stimuli.
The results show that environmental exposure to the urbanized coastal waters off Greater Los Angeles
does in fact result in endocrine disruption. The results also indicate that there is no difference between
one portion of the coastal water and another with regards to endocrine disruptive potential. The
potential is uniformly distributed over the coastal waters. Errors include inadequate sample size, in
adequately quantifiable data, and questionable sourcing of controls which may have affected the re-
sults.

88 CORRELATION DYNAMICS IN ACIRCUIT MOLECULES@ WITH CHAOTIC LINKS
J. Manasson and V. A. Manasson. WaveBand Corporation, Los Angeles, CA, 90501

Correlation phenomena in original circuit networks based on chaotic links with different structural
complexities and different dimensions were studied. The circuits demonstrate rich spatio-temporal
behavior including a new phenomenon, remote correlation, when correlation between remote nodes is
stronger than correlation between any other pair of neighboring nodes. This work also demonstrates
a new jitter generator circuit with possible applications to secure communications.

A new approach was used to synthesize the networks. The network geometry mimics chemical
molecules with high spatial symmetry. The Abonds@ connecting circuit nodes (positions of Aatoms @ )
are replaced with chaotic links based on the jitter generator. Waveforms, phase portraits, and power
spectrums were investigated, and correlation functions were calculated for interesting cases. The results
contribute to the spatio-temporal phenomena in complex systems.

89 DISTRIBUTION OF OXIDATIVE AND GLYCOLYTIC ENZYMES IN ELECTROCYTES OF
PHYLOGENTICALLY DIVERSE SPECIES OF FISH

Edward Smetak, Jr., La Habra High, SCJAS RTP, and Dr. Glenn Kageyama, Mentor, California
State Polytechnic University, Pomona, Department of Biological Sciences, Pomona, CA, 91768

Electric fish generate energy and produce an electric current from electrocytes which are derived
from muscle tissue. The type of energy metabolism that creates ATP in the electrocytes can vary,
possibly depending on the type of muscle the electrocyte has evolved from, either fast or slow. The
goal of this research is to determine how various electric fish generate ATP in their electric organs.
Enzyme histochemistry and immunohistochemistry was used to localize glycolytic and oxidative met-
abolic enzymes in electrocytes of the electric fish Gnathonemus, commonly known as the elephantfish.
These findings were then compared to those found in other species of electric fish, such as Sternarchus
albifrons. By examining the distribution of metabolic enzymes, in can be seen that electrocytes utilize
one or both metabolic pathways, either oxidative respiration or glycolysis, in the production of ATP.

90 THE EFFECT OF LIGHT ON THE ACCUMULATION OF THE NUCLEAR-ENCODED
psbA BINDING PROTEINS IN VASCULAR PLANTS

Monica Singh, Maya E. Mazon, Laura Arce and Amybeth Cohen, Dept. of Biological Science,
California State University, Fullerton, CA 92834-6850

In the unicellular green alga Chlamydomonas reinhardtii, the RB47 proteins accumulate in response
to light, while the RB38 and RB60 protein accumulates constitutively. These three nuclear-encoded
proteins bind to the 5’-untranslated region of the chloroplast-encoded psbA mRNA to initiate the
synthesis of the photosynthetic D1 protein. Using immunoblot analysis and antibodies raised against
RB38, RB47 and RB60 from C. reinhardtii, we hypothesized that the protein accumulation would
occur in one of three manners: constitutive, chloroplast-induced, or light-induced in two vascular

ABSTRACTS A5

plants: bean (Phaseolus vulgaris) and pea (Pisum sativum) using C. reinhardtii as our control. The
objective was to show that C. reinhardtii and vascular plants contained the same proteins involved in
D1 synthesis, in hopes that we could one day apply what is known about the photosynthetic processes
in C. reinhardtii to vascular plants and thus further enhance our understanding of photosynthesis. The
anti-RB38 antibody recognized a 54.9-kD protein in P. vulgaris. In light and developmental studies,
this 54.9-kD protein accumulates in light- and dark-grown bean shoots, as well as dark-grown bean
roots. Anti-RB60 recognized a 60-kD protein in both shoots and roots, although reduced in both dark-
grown shoots and roots, as compared to light-grown shoots. The anti-RB47 recognized a 47-kD protein
in only light-grown shoots, and not dark grown shoot or roots.

92 THE EFFECTS OF ENDOTHELIAL POLARITY AND ALZHEIMER’S DISEASE ON
MONOCYTE MIGRATION IN THE HUMAN BRAIN

Wei Liang. Alhambra High School, Alhambra, CA, 91801; University of Southern California,
Department of Biochemistry and Molecular Biology, Los Angeles, CA

Amyloid $-peptide (A$) is a protein present on both sides of the human blood-brain barrier (BBB).
In patients with Alzheimer’s disease and other with A$-related disorders, it accumulates, increasing
the migration of monocytes across the BBB by interacting with certain proteins, two of which were
shown to be A$ receptor RAGE (receptor for advanced glycation end products) and PECAM- 1 (platelet
endothelial cell adhesion molecule). This study examines the effect of polarity (the presence of AB
on the luminal or abluminal side of the BBB) on A$, RAGE, and PECAM-1 mediated monocyte
migration. Transwell chambers were used to simulate the brain endothelium and A$ was added to the
top (luminal) or bottom (abluminal) compartments to induce the migration of monocytes across a
monolayer of human brain microvascular endothelial cells (HBMVEC). Results from normal as well
as Alzheimer’s disease endothelial cells were compared. The results show that in normal endothelium,
luminal AB is able to induce a higher rate of migration, while in Alzheimer’s endothelium, polarity
of AB is insignificant. Furthermore, Alzheimer’s endothelial cells react more readily with AB, espe-
cially when it is abluminal, resulting in increased migration of monocytes as compared to normal
endothelial cells.

93 DNA STRUCTURE AFFECTS SODIUM BISULFITE CONVERSION OF NUCLEOTIDES

D.M. Chen and C.L. Hsieh. University of Southern California/Norris Cancer Center, Department
of Urology, Los Angeles, CA, 90033-0804

Sodium bisulfite conversion efficiency is essential in mapping methylation patterns in DNA se-
quences. Past research has shown that sequences with cytosines adjacent or near methylated cytosines
acquire partial resistance to full conversion. Different oligonucleotides with inverted repeats were
designed to form hairpin loop structures to test efficiency of the sodium bisulfite reaction method. The
loop structures had different arrangement of bases and were tested for the order in which the cytosines
in the stem of the structure can no longer be fully converted under the reaction temperature of 55E
Celsius. Each sequence had 2 matching base pairs at the base of the structure. The status of the
different sequences (DC-1, DC-2, DC-3, DC-4) after undergoing the sodium bisulfite reaction turned
out to be full conversion. Hairpin loop structures with a small number of matching bases at the foot
of the sequence do not affect the efficiency of the sodium bisulfite reaction.

94 THE EFFECTS OF UROKINASE-TYPE PLASMINOGEN ACTIVATOR (uPA) INHIBITION
ON CRANIAL NEURAL CREST MIGRATION

H.L. Marr and M.A.J. Selleck. University of Southern California, Keck School of Medicine,
Department of Cell and Neurobiology, Los Angeles, CA, 90089

Neural crest cells play an important role in embryonic development as they differentiate into com-
ponents of the central and peripheral nervous systems, vascular system, and muscle tissue. Urokinase-
type Plasminogen Activator (uPA) has been speculated to convert plasminogen into plasmin, which
degrades the extracellular matrix and provides a pathway through which neural crest cells migrate. In

46 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

order to determine the direct role uPA plays in neural crest migration, young chick embryos were
cultured (either in New culture or Window culture depending on embryo stage) in the presence of a
1mM Amiloride solution, a diuretic drug known to inhibit uPA. By knocking out uPA, it is possible
to deduce the role it plays in cranial neural crest migration. Performing immunohistochemistry labeling
for Hnk-/ has allowed us to examine the patterns of crest migration. Results indicate that uPA is vital
for migration: its inhibition prevents the migration of neural crest and also plays a part in preventing
neural tube closure. Its greatest effect is seen in young stage 4 embryos, where a drastic decrease in
migration is shown as compared with control embryos. Knowledge of neural crest migration and
neural tube closure requirements can be applied to induce migration in crest cells that have failed to
do so.

95 GENETICS OF DAUER LARVAE FORMATION IN CAENORHABDITIS BRIGGSAE

S. Phan and I. Takao, California Institute of Techology, Department of Biology, Pasadena, CA,
SINS)

Caenorhabditis briggsae, a sister species of Caenorhabditis elegans evolved from evolution about
60,000 years ago. Exactly how different these two nematode species is not clearly understood. To
tackle the problem, a comparison of the dauer larvae stage in which nematodes can undergo for six
month without feeding and all growth development halted can provide a leading clue to the differences
exhibited by both nematode species. A mutagenesis was conducted to the wildtype strain of C. briggs-
ae to screen for dauer mutants to compare with the C. elegans dauer mutants. A series of test was
conducted to analyze the mutants of C. briggsae. In conclusion, the analysis showed that the daf-13
gene in C. elegans, which is X-linked and responsible for causing Sodium Dodecyl Sulfate (SDS)
sensitive in C. elegans has a different function in C. briggsae. Also, the daf-4 gene that causes dauer
mutation is not temperature sensitive in C. briggsae than in C. elegans.

96 RETROVIRAL-MEDIATED TRANSFER AND EXPRESSION OF THE NEOMYCIN AND
HYGROMYCIN B DRUG RESISTANCE GENES

Annie Li and Vicky Sung, Dr. Michael Lai Research Group, University of Southern California
School of Medicine, Department of Molecular Biology and Immunology, Los Angeles, CA,
90033

The application of an efficient retroviral vector serves as an important tool in gene therapy and
genetic analysis of a variety of genes. Transferring a drug resistant gene is primarily useful during
selection of transformed cells containing both the drug resistance gene and a desired gene. Although
past studies have succeeded in transferring the neomycin drug resistance gene (NeoR) within cells,
no studies have been conducted with the hygromycin B drug resistance gene (HygroR) or both HygroR
and NeoR. In this experiment, the Murine Leukemia Virus (MLV) pseudotyped with the Vesicular
Stomatitis Virus glycoprotein (VSVg) was used to transduce the NeoR and HygroR within a 293 cell
line, human embryonic kidney cell line. 48 hours after infection, cells expressing drug resistance were
selected by applying 500 -g/ml of G418 and/or 150 -g/ml of hygromycin B to 10% Fetal Bovine
Serum (FBS) Dulbecco’s modified Eagle’s medium (DMEM). The number of 293 cells surviving toxic
levels of G418 and/or Hygromycin B drug application was counted weekly with the Trypan Blue
Exclusion Assay. This system successfully transferred and expressed the drug resistance genes within
293 cells, but was not able to sustain the expression of hygromycin B resistance for more than a week.
Currently, the neomycin resistant cells are still being cultured and experimented with in order to
determine the length of time of its gene expression.

97 BROCA’S AREA’S CRITICAL ROLE IN IMITATION

Jake Marcus, Crossroads School, Santa Monica, CA, 90404, Marc Heiser, UCSE San Francisco,
CA, 94143, Fumiko Maeda, Marco Iacoboni, Ahmanson Lovelace Brain Mapping Center, Los
Angeles, CA, 90095

To determine if Broca’s area plays a critical role in human imitation, we conducted a repetitive
transcranial magnetic stimulation (rTMS) study, transiently disrupting cortical activity in three sites:

ABSTRACTS AG,

the left inferior frontal gyrus (Broca’s area), right inferior frontal gyrus, and an occipital control
condition. Stimuli consisted of sequences of key presses by a left hand (action to be imitated). The
subjects had a button pad and used the right hand to press the keys instructed by the ‘action to be
imitated’ (imitation task). To ensure the r™MS pulses were not stimulating motor paths causing inter-
ruption in the imitation task, a visuomotor control task was designed. In this task spatial cues (red
dots appearing over the keys) instructed the subjects which keys to press. No differences were observed
between the inferior frontal cortexes and occipital site. If Broca’s area were critical to imitation then
the subject would not perform well in the imitation task while Broca’s area was disrupted. Stimulation
of the occipital control site should yield the highest accuracy. The results confirmed our predictions
supporting the concept that Broca’s area is critical to imitation. Broca’s area, a language processing
and speech production region, now also demonstrated to be critical to imitation, suggests that imitation
may have been an evolutionary precursor of more complex communicative abilities in humans.

98 OXIDATION OF SUBSTIUTED PHOSPHINES WITH SINGLET OXYGEN: INTRA- VS.
INTER-MOLECULAR PATHWAYS

Timothy Dong, Dr. Matthias Selke, California State University, Los Angeles, Dept. of Chem-
istry, Los Angeles, CA 90032

Reaction between singlet oxygen and tris(ortho-methoxyphenyl)phosphine resulted in the formation
of both phosphine oxide and orthomethoxyphenyl-di(orthomethoxyphenyl) phosphinate, more simply
referred to as insertion product. The insertion product resembles phosphine oxide except for the ad-
ditional presence of an oxygen atom located between the phosphorus and carbon atom of one of the
three phenyl rings attached to the phosphorus atom. By comparing the product distribution of phos-
phine oxide and insertion product, a ratio of the rate constants for the oxide pathway and the insertion
pathway was obtained. From this, it has been concluded that formation of insertion product increases
with polarity and decreases with increased concentration. It is believed that formation of phosphine
oxide proceeds via the inter-molecular pathway, while the insertion product proceeds via the intra-
molecular pathway. These results can also be applied toward controlling the distribution of product
yield of phosphine oxidation based on the initial concentration of phosphine used and the polarity of
the solvent employed—providing a convenient alternative in mediating an otherwise complicated
combination of intra- and inter-molecular reactions.

99 INFLUENCES ON THE SELECTION OF SCIENCE AS A STUDY AND CAREER
Lisa Marin-Burkhart, Claremont Graduate University

Mediocre performance of U.S. students on national and international science assessments continues
despite years of science education reform. Is there evidence of success for the various initiatives
seeking to increase equity and diversity among scientists? Can we truly achieve “‘science literacy for
all’? How do we answer the question, ““Who will do the science of the future?”

This study asked a sample of scientists and college science majors (N = 64) spanning the ages of
18—65 to reflect upon influences that helped shape and develop their interest in science. Using both
Likert-scale items and personal notations, respondents provided insights into the growth of those who
do become scientists. Similarities and differences between genders and disciplines as well as among
age cohorts were assessed. A distinct improvement in the perception of gender bias was noted, with
written responses revealing dramatically how times have changed.

100 A COMPARISON OF THE VOCALIZATIONS OF TWO SPECIES OF FLYING FOXES IN
THE SAMOAN ARCHIPELAGO

Eiler, K; J. Newmark; B. Drummond; C. Stewart; and S. Banack, California State University,
Department of Biological Science, Fullerton, CA 92831

Most mammals use audible vocalizations to communicate but few studies have documented the
extent, range, or distinctiveness of these calls. We report acoustic communication in two species of
flying fox that coexist in the Samoan archipelago, Pteropus samoensis and P. tonganus. Flying foxes

48 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

are large fruit and nectar eating bats restricted to the Old World. They are members of the suborder
Megachiroptera and the family Pteropodidae. There are 60 recognized species in the genus Pteropus.
Species include the largest living bats, with wingspans up to 1.7 meters. No species of flying fox
echolocates, a trait ubiquitous in Microchiropterans. Communication within and between species in-
volves audible calls but remains largely unstudied. We compared the vocalizations of P. samoensis
and P. tonganus from Tutuila, American Samoa in June 2001 using a Senheiser MKH-70 P 48 direc-
tional microphone, Sony digital audio tape recorder TCD D 10 PRO II, and Canary bioacoustical
software for analysis. P. samoensis is a largely diurnal species that roosts within trees either singly
or in small family groups (male, female, and single offspring). It is highly territorial and actively
defends its territory against intruders. Vocal communication is the primary means used to deter other
flying foxes from landing within an occupied territory. P. tonganus is a nocturnal species and roost
in large noisy camps with up to 5000 animals congregated in adjacent trees. Interactions between the
two species are minimal. Variation between populations and species were examined from sonograms
using five parameters: peak frequency, pulse rate, maximum frequency, frequency | (high frequency
of the peak harmonic) and number of harmonics.

Name

Mia Adreani

Dr. M. James Allen
Jessica Altstatt
Jack W. Anderson
Jason Bae
Jonathan Baskin
Steve Bay

Kelly Boyle
Andrew Brooks
Jeff Brown

Jeffery Burkhart
Don Cadien

Jay C. Carroll

Dan Cartamil
Debbie Chen

GY. Chen
Christiana Chen
Wesley Chun
Laurie Clarke

Risa Cohen

Erin Cox

A. G. Craig
Matthew T. Craig
Matthew T. Craig
Jeff Crooks

Mike Curtis
Roman Deniskin
Michael L. Domeier
Timothy Dong
Karen Drewe
Sabrina Drill

Mary Elaine Dunaway
Karen Eiler

Brad Erisman

Ana Ferrus-Garcia
Donovan P. German
Richard Gossett
Karen Green
Robert Grove
Daniel Guthrie
Gerald Hannes
Sarah K. Henkel
Alensandra Hernandez
Lawrence Honma
Michael H. Horn
Michael H. Horn
Mary Ann Irwin
Bill Isham

Mark Jennings
Burton Jones

Alphabetical List of all Presenters.

Abstract no.

70
9
66

Name Abstract no.

Jennifer H. Jones
Julianne Kalman
Krista Kamer

Kathy Keane

Scott Kimura

Amruta Kulkarny
Ronit Lavie

Annie Li

Wei (David) Liang
Christina Luzier

Julia Manasson
Megan Marcotte

Jake Marcus

Lisa Marin-Burkhart
Henry Marr

Alan Mearns

Keith Merkel

Tim Mikel

Steven N. Murray

E. C. Nestler

James A. Noblet
Gabriela Noriega-Carlos
Wheeler North

Mark Ohman

Yannis Papastamatiou
Lalit Patel

Christy Pattengill-Semmens
Shirley Phan

Daniel Pondella II
Ananda Ranasinghe
Brendan Reed
Veronica Rodriguez-Villanueva
Kenneth Schiff

V. Anne Short
Christina Simokat
Monica Singh
Constantinos Sioutas
Edward Smetak Jr.
Paul E. Smith
Anthony P. Spina
Camm Swift

Camm Swift
Constance Vadheim
Matthew Vandersande
Ronald G. Velarde
Doris Vidal

Mark Walberg

Ray Wilson

Rachel A. Woodfield

71
37
20
44
58
83
38
96
92
28
88
29
97

CONTENTS

Student Award Winners

Sov AWA DN Rts Ae GA eee te ee nea 1
Schedule of Program for 2002 Annual,Mectng 22 3
PRT SURACES Sascha BU oa OI ils 1g al Sart GEO eh ch A A ea 12
Alphabetical list of presenters at 2002 Annual Meeting _ inside back cover

COVER: Holotype of Lile negrofasciata (C1:2032), adult female, from Bahia de Guasimas, Sonora,
Mexico. Photograph by Gorgonio Ruiz-Campos.

gy’ ISSN 0038-3872

AOULHERN: CALIFORNIA , ACADEMY -OFj SCIENCES

BULLETIN

Volume 101 Number 3

BCAS-A101(3) 103-146 (2002) DECEMBER 2002

Southern California Academy of Sciences
Founded 6 November 1891, incorporated 17 May 1907

© Southern California Academy of Sciences, 2002

OFFICERS

Ralph G. Appy, President
Judith Lemus, Vice-President
John Dorsey, Secretary
Daniel A. Guthrie, Treasurer
Daniel A. Guthrie, Editor
David Huckaby, Past President
Robert Grove, Past President
Hans Bozler, Past President

BOARD OF DIRECTORS

2000—2003 200 1—2004 2002—2005
James Allen Brad R. Blood Ralph G. Appy
John Dorsey Chuck Michell Jonathan N. Baskin
Judith Lemus Daniel Pondella Cheryl Hogue
Martha and Richard Raymond Wells John W. Roberts
Schwartz Raymond Wilson Gloria J. Takahashi

Susan E. Yoder

Membership is open to scholars in the fields of natural and social sciences, and to any person interested
in the advancement of science. Dues for membership, changes of address, and requests for missing
numbers lost in shipment should be addressed to: Southern California Academy of Sciences, the Natural
History Museum of Los Angeles County, Exposition Park, Los Angeles, California 90007-4000.

Proteasional WMembers: 2 cy el sais eg ee a ae oa Me Si inc Ue ed ok
student Members <2". kya) cel heey egret Nev oo ee oe
Memberships in other categories are available on request.

Fellows: Elected by the Board of Directors for meritorious services.

The Bulletin is published three times each year by the Academy. Manuscripts for publication should
be sent to the appropriate editor as explained in “Instructions for Authors” on the inside back cover
of each number. All other communications should be addressed to the Southern California Academy
of Sciences in care of the Natural History Museum of Los Angeles County, Exposition Park, Los
Angeles, California 90007-4000.

Date of this issue 20 November 2002

© This paper meets the requirements of ANSI/NISO Z39.48-1992 (Permanence of Paper).

SOUTHERN CALIFORNIA ACADEMY
OF SCIENCES

CALL FOR PAPERS
2003 ANNUAL MEETING
May 2-3, 2003
CALIFORNIA STATE UNIVERSITY

NORTHRIDGE

Woo, \90!
RPORATED.
O Se)

S ANGEL

Contributed Papers & Posters: Both professionals and students are welcome to submit abstracts for
a paper or poster in any area of science. Abstracts are required for all papers, as well as posters, and
must be submitted in the format described below. Maximum poster size is 32 by 40 inches.

Symposia: The following symposia are planned at the present time. If you wish to participate or to
organize any additional symposia, please contact the organizer or the Academy President, Ralph Appy
(310 732 3497) rappy @portla.org. Organizers should have a list of participants and a plan for reaching
the targeted audience.

Reef Ecology—Dan Pondella: pondella@oxy.edu
Science Ed—Judy Lemus: jdlemus @ usac.edu

Declining Fisheries—Jim Allen: jima@sccwrp.org
Estuarine Ecosystems—Ray Wilson: rwilson! @csulb.edu

Air Quality—Ralph Appy: rappy@portla.org

Terrestrial Non-indigenous/Exotic Species—Dan Guthrie: dguthrie @jsd.claremont.edu

Zoo-archeology—Dan Guthrie: dguthrie @jsd.claremont.edu

Bioremediation—John Roberts: jroberts @ dhvx20.csudh.edu

There will be additional sessions of Invited Papers and Posters and of papers by Junior Academy
members.

Abstracts of presented papers and posters will be published in the August issue of the Bulletin.

Student Awards: Students who elect to participate are eligible for best paper or poster awards in the
following categories. Biology: ecology and evolution, biology: genetics and physiology, physical sci-
ence. A paper by any combination of student and professional co-authors will be considered eligible
provided that it represents work done principally by student(s). In the case of an award to a co-authored
paper, the monetary award and a one year student membership to the Academy will be made to the
first author only.

For further information on posters, abstracts, registration and deadlines, see the Southern California
Academy of Science web page at: www.lam.mus.ca.us/~scas/

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Bull. Southern California Acad. Sci.
101(3), 2002, pp. 103—117
© Southern California Academy of Sciences, 2002

Feeding Ecology of Juvenile Kelp Bass (Paralabrax clathratus) and
Barred Sand Bass (P. nebulifer) in Punta Banda Estuary,
Baja California, Mexico

Manuel Mendoza-Carranza and Jorge A. Rosales-Casian

Departamento de Ecologia, Centro de Investigacion Cientifica y Educacion
Superior de Ensenada (CICESE), P.O. Box 434844,
San Diego, California 92143-4844 U.S.A.
email: mcarranza@ vhs.ecosur.mx
email: jrosales @ cicese.mx

Abstract.—Kelp bass (Paralabrax clathratus) and barred sand bass (P. nebulifer)
diets are analyzed between seasons at Punta Banda estuary, Baja California, Méx-
ico (1992-1993). Beam-trawl and otter-trawl tows (5m depth) collected kelp bass
of 40-110mm SL range, and P. nebulifer of 30-230mm; overall, gammarid am-
phipods dominated their diets in index of relative importance, (IRI; 79.4% and
50.9%, respectively). In kelp bass, gammarids had highest IRI in summer (89.3%)
and winter (74.9%), with a fish occurrence of 1.6—12.2%, and eelgrass remains
of 0.8-7.1%. In P. nebulifer, summer to winter IRI of gammarids were 40.0—
88.4%, and occurrence (43.8—65.6%), numeric (65.2—95.0%), and weight (2.5—
49.8%). Kelp bass and barred sand bass numeric diet breadth in summer were
0.038 and 0.12, respectively, and 0.031 and 0.013 in winter; for kelp bass, weight
diet breadth were 0.031—0.27, and for barred sand bass 0.18—0.26. Dietary overlap
between basses was low (<0.60), and by seasonal numbers (<0.49) and weights
(<0.24). Numeric diet breadth was influenced by small prey with high numeric
dominance (gammarids). Despite the low niche overlap at Punta Banda estuary,
both species showed close trophic affinities by occupying eelgrass beds and ad-
jacent areas.

The Punta Banda estuary and San Quintin bay are the two most extensive
coastal lagoons along the Northern Pacific Coast of Baja California, México (Ro-
sales-Casian 1997a,b). These lagoons are very important nursery grounds, pro-
viding abundant food and a decreased predation risk for many juvenile fishes
(Navarro-Mendoza 1985; Castro-Longoria and Grijalva-Chon 1988; Hammann
and Rosales-Casian 1990; Rosales-Casian and Hammann 1993: Rosales-Casian;
1997a,b). Some of the fish species inhabiting these environments are of com-
mercial and recreational importance, including California halibut (Paralichthys
californicus), kelp bass (Paralabrax clathratus) and barred sand bass (Paralabrax
nebulifer) (Hammann and Rosales-Casian 1990; Ono 1992; Rodriguez-Medrano
1993; Rosales-Casian 1997a,b).

In Punta Banda estuary, juvenile kelp bass and barred sand bass are important
constituents of the assemblage, and are abundant throughout the year (Rosales-
Casian and Hammann 1993; Rosales-Casian 1997a,b) exhibiting a spatial and
temporal overlap (Salome-Sanchéz 1994, Pintos-Teran 1994, Mendoza-Carranza
1995). These species present a similar morphology (Feder et al. 1974), and this

103

104 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

Todos Santos

Bay

116° 40’ 116°48’

Fig. 1. Beam-trawl and otter trawl sampling sites for kelp bass and barred sand bass collections
in the Punta Banda estuary (1992-93).

can imply a possible competition for food (Turner et al. 1969). Therefore, resource
partitioning is an important issue in understanding the structure and dynamics of
species with similar habits and morphology (Hyslop 1980, Cabral 2000). This
study describes and compares the feeding habits of kelp bass and barred sand
bass in the Punta Banda estuary, and considers the seasonal variation in diet.

Methods
Study Area

The Punta Banda estuary is located in the North Pacific of Baja California
Peninsula at southern side of Todos Santos Bay, Ensenada (31°40’—31°48'N,
116°04’—116°40'W). The L-shaped estuary covers an area of 21 km’, communi-
cating with the bay through a narrow mouth (<200 m) in its northwest side; it is
separated from the bay by a 7.5-km-long sand bar (Figure 1). The estuary has a
median depth of 5 m, and its channel can reach 8 m depth. It is a protected
habitat, with Zostera and Spartina beds (3.3 km?), mud and sandy bottoms (Ibarra-
Obando and Poumian-Tapia 1992).

Sampling Methods

Samples were taken monthly from May 1992 to April 1993 (Rosales-Casian,
1997a,b). Collections were made with a beam-trawl (1.6 m wide, 0.4 m high, 3

FEEDING ECOLOGY OF BASS IN PUNTA BANDA, BAJA CALIFORNIA 105

mm mesh netting) and an otter-trawl (2.5 m by 7.5 m, 5 mm mesh in body and
3 mm in bag end). Five-minute tows (four monthly replicates) were made along
the 5 m depth contour at approximately 0.75—1.0 m/sec (1.5—2.0 knots).

Kelp bass and barred sand bass were measured (standard and total length) to
the nearest millimeter, and weighed (total and somatic weight) to the nearest gram.
The stomachs were extracted by cutting the anterior side of the esophagus and
pylorus; they were fixed in 10% formaldehyde buffered with sodium borate.

Seasonal Classification

Bass were classified into two seasonal groups based on monthly surface and
bottom temperature (measured with a reversing thermometer) to examine possible
variation in diet. The two seasonal periods were: summer (April—October) with
warm temperatures (19.9°C + 1.4 SD); and winter (November—March) with cold
temperatures (16.6°C + 1.1 SD) in accordance with Rosales-Casian (1997a,b),
and Mendoza-Carranza and Rosales-Casian (2000).

The seasonal sizes of kelp bass and barred sand bass were tested for homo-
geneity of variances using Levine’s test (Zar, 1984). We used the multiple analysis
of variance (MANOVA; Zar, 1984) to test for statistical differences among stan-
dard lengths of kelp bass and barred sand bass seasonal groups.

Stomach Content Analysis and Data Analysis

The contents of 136 (58 summer, 78 winter) kelp bass and 134 (100 summer,
34 winter) barred sand bass stomachs were examined. Prey items were identified
to the lowest taxonomic level, counted, and wet weighed to the nearest 0.001 g.
After data collection, prey items were grouped into higher-level taxonomic cate-
gories.

The relative importance of each prey item was expressed as percent of numer-
ical abundance (%N), weight (%W) and frequency of occurrence (%F) (Hyslop,
1980), and were used to calculate the index of relative importance (modified from
Pinkas et al. 1971):

IRI = (®N + %W) X WEF

Diet differences between species and seasons were tested using the G-statistic
(Crow 1981; Sokal and Rohlf 1981).

Feeding activity was evaluated by the feeding intensity index, expressed as the
total weight of food, divided by the somatic weight of fish and expressed as
percentage. To detect seasonal differences of feeding intensity by species, we used
the non-parametric Kruskal-Wallis ANOVA because homogeneity of variances
was rejected (P < 0.01, Zar 1984). The vacuity index was defined as the per-
centage of empty stomach (Hyslop 1980).

Diet breadth was calculated using Levin’s standardized index (Hurlbert 1978;
Krebs 1989):

Ba 1) XC iPaper

where B; = Levin’s standardized index for predator i; p, = proportion of diet of
predator 7 that is made up of prey j, and n = number of prey categories. The
index varies from 0 to 1; low values indicate diets dominated by few prey items
and high values indicate generalist diets (Gibson and Ezzi 1987; Krebs 1989).

106 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

Frequency (%)

35 SUMMER
30
25
20
15
10
; i
Sime fis
40 60 8

0 0 100 120 140 160 180 210 230 250

Frequency (%)
No
So

25
15
: |
S)
0 SBS
0 40 60 80

100 120 140 160 180 210 230 250
Standard length (mm)

Fig. 2. Length-frequency distribution of kelp bass _] and barred sand bass IJ during summer and
winter from Punta Banda estuary.

Diet overlap was calculated using the simplified Morisita’s index (Krebs 1989,
Hall et al. 1990):

(Cg zp Pi * rs] (> (Da r')
j j

Where C;, = the simplified Morisita’s index for predators i and k; p, and p,; =
proportions of each food item inside predator’s stomachs. Diet overlap increases
as the Morisita’s index increase from 0 to 1. Overlap is generally considered to
be biologically significant when the value exceeds 0.60 (Wallace 1981; Wallace
and Ramsay 1983; Labropoulou and Eleftheriou, 1997). Diet and overlap breadth
was estimated using the numerical abundance and biomass of prey items found in
the stomachs. Bias-corrected bootstrap 95% confidence intervals, based on 1000
simulations, were used to estimate the reliability of these indices (Efron 1979, Efron
and Tibshirani 1986, Hall et al. 1990, Labropoulou and Eleftheriou, 1997).

Results

Size Structure of Predator Groups

During summer, kelp bass ranged from 40 mm to 110 mm with a maximum
frequency (37.5%) in the 60 mm size class; barred sand bass size ranged from
30 mm to 230 mm, with maximum frequency (23.6%) in the 140 mm size class
(Figure 2a). During winter kelp bass ranged from 50 mm to 110 mm, with max-

107

FEEDING ECOLOGY OF BASS IN PUNTA BANDA, BAJA CALIFORNIA

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110 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

imum frequency (29.8%) at 80 mm; in barred sand bass the minimum size class
was 60 mm and maximum 160 mm, maximum frequency (28.1%) was observed
in the 100 mm size class (Figure 2b). The size of bass groups had homogeneous
variances (F = 2.6, P > 0.01), and MANOVA test revealed significant differences
between seasons (F = 59.6, P < 0.01) and between species (F = 228.5, P <
0.01), no interaction among species and seasons were detected (F = 181.7, P <
0.01). Post hoc comparison with Duncan’s multiple range test, showed no differ-
ences between kelp bass and barred sand bass winter groups only.

General Food Habits

Kelp bass diet consisted of ten prey groups: eelgrass fragments, cnidarians,
mollusks, polychaetes, mysids, decapods, gammarids, caprellids, isopods, and
fishes. Gammarids were the most important food item in the kelp bass diet, with
the highest value of IRI (79.4%), and decapods ranked second with 12.9% (Table
1). Highest values of frequency of occurrence (75.4%) and numeric percentage
(84.2%) were found for gammarids also. The highest values of weight percentage
were the decapods (38.7%). The principal gammarid species was Corophium
acherusicum (Table 1).

Besides the prey groups mentioned for kelp bass, the diet of barred sand bass
were sipunculids, cumaceans, and echinoderms. Gammarids were the dominant
food item, with 50.9% of IRI, fish ranked second with 1.2% (Table 1). Gammarids
had the highest frequency of occurrence (49.2%) and numeric percentage (74.0%).
Fishes showed the highest weight percentage (44.8%). Gammarids were domi-
nated by genus Ervichtonius sp., and food fishes were unidentified teleosts and the
anchovy, Anchoa sp. (Table 1).

Seasonal Variation of Diet

In kelp bass diet, the dominance of gammarids was similar in summer and
winter, although their importance slightly diminished from 83.9 to 74.9% of total
IRI. This can be attributed to the decrease in percent weight of gammarids from
46.6% in summer to 9.5% in winter. A frequency occurrence increase from sum-
mer to winter was observed in eelgrass fragments (0.8 to 7.1%) and fishes (1.6
to 12.2%). Mysids and caprellids were present in summer only. Weight percent
was dominated by gammarids in summer (46.6%) (Figure 3a) and decapods in
winter (48.8%; Figure 3a,b). Significant differences in the numerical abundance
of prey groups between summer and winter diet (G = 168.1, P < 0.05) were
found.

In barred sand bass diet, an importance increase in gammarids from summer
(40.0% IRI) to winter (88.4% IRI) was observed (Figure 3c,d). This change was
related to the increase of frequency of occurrence (43.8 to 65.6%), numeric (65.2
to 95.0%) and weight (2.5 to 49.8%) percentages from summer to winter (Figure
3c,d). Decapods diminished in importance from summer (18.3% IRI) to winter
(5.0% IRI), with a seasonal diminution of numeric percentage (6.5% in summer
to 0.90% in winter). In summer, fishes (46.2%), mollusks (23.4%) and decapods
(21.8%) dominated by weight, and gammarids during winter (Figure 3c,d). The
G-statistic revealed significant differences in the numerical abundance of prey
groups between seasons (G = 335.8, P < 0.05). Mean feeding intensity in kelp
bass increased from 1.1 (+1.0 SD) in summer to 2.0 (+5.6 SD) in winter (Figure

FEEDING ECOLOGY OF BASS IN PUNTA BANDA, BAJA CALIFORNIA A

Paralabrax clathratus
SUMMER WINTER
80 Gammarids 92 Gammarids
79 91
15 15
N 10 nee Mysidaceans N 10

Mollusk
Decapods Isopods

Caprellids Decapods| Fishes

Fishes

W 10 4.8% | 0.2% W 10
(613) (33)
15 S 0.7% 15
6 | | (623) (25) oa
47 83.9% 28
(10559)
F
20% 20%
a b
Paralabrax nebulifer
SUMMER WINTER

Gammarids

66 95
Gammarids
65 94

Fishes Isopods

Decapods
wee VL
Wt

Echinoderms

40.0%
(2943)

(1356) :

46 +
re 446.2% (9500)
(1200)

F

20% 20%

c d

Fig. 3. Relative importance by percent number (N), percent weight (W) and percent frequency
occurrence (F) of principal prey of kelp bass during summer (a), and winter (b) and barred sand bass
during summer (c) and winter (d) from Punta Banda estuary. Below bars: IRI percentage and IRI
values (parenthesis).

4). Significant differences in feeding intensity between seasons (H = 145.7, P <
0.01) were found. In barred sand bass, a decrease of feeding intensity from 1.0
(+£1.6 SD) in summer to 0.6 (£0.4 SD) in winter (Figure 4) was observed. Sig-
nificant differences were observed in feeding intensity between seasons (H = 6.1,
f= (0.05).

In kelp bass, a significant (x? = 15.4, P < 0.01) increase in empty stomachs
was found from summer (5.1%) to winter (29.4%) (Figure 5). In barred sand bass,
no differences (x? = 0.8, P < 0.1) was observed in empty stomachs (4.0% sum-
mer, 5.8% winter; Figure 5).

112 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

Feeding intensity index (%)

SUMMER WINTER SUMMER WINTER

Paralabrax clathratus Paralabrax nebulifer

Fig. 4. Seasonal changes in feeding intensity index by kelp bass and barred sand bass from Punta
Banda estuary (error bars are standard deviation).

Diet Breath and Overlap

In both kelp bass and barred sand bass, the numeric diet breadth was highest
during summer (0.038 and 0.12) and diminished in winter (0.031 and 0.013;
Figure 6). Homogeneity of variances between summer and winter groups of kelp
bass was accepted (F = 0.7, P < 0.05), and ANOVA showed that numeric diet
breath was significantly different between seasons (F = 7.0, P < 0.01). Homo-
geneity of variances was not accepted in winter groups of barred sand bass (F =
1558.4, P < 0.01), and Kruskal-Wallis ANOVA showed that numeric diet breath
was significantly different between seasons (H = 1567.8, P < 0.01).

With respect to diet weight breadth for kelp bass, values were 0.31 in summer,
and 0.27 in winter. In barred sand bass, and increase of weight diet breadth was
observed from summer (0.18) to winter (0.26; Figure 6). Variances were homo-
geneous of weight diet breadth between seasons for both species (kelp bass F =
2.4, P > 0.05; barred sand bass F = 0.9, P > 0.05). Weight diet breadth of both
species was significantly different between seasons (Kelp bass: F = 107.2, P <
0.01; barred sand bass: F = 702.6, P < 0.01).

Empty stomachs (%)
= = NO N w&
i=) ol So on oO

oa

SUMMER WINTER SUMMER WINTER

Paralabrax clathratus Paralabrax nebulifer

Fig. 5. Seasonal changes in vacuity values determined by kelp bass and barred sand bass from
Punta Banda estuary.

FEEDING ECOLOGY OF BASS IN PUNTA BANDA, BAJA CALIFORNIA 113

0.5

0.4

0.3

0.2

Levin’s index

0.1

SUMMER WINTER SUMMER WINTER

Paralabrax clathratus Paralabrax nebulifer

Fig. 6. Seasonal changes in numeric HM and weight [| diet breath for kelp bass and barred sand
bass from Punta Banda estuary (error bars are 95% bootstrap confidence intervals).

Dietary overlap between kelp bass and barred sand bass were relatively low
(<0.60), although increased from summer to winter for both numeric (0.44 sum-
mer, 0.49 winter) and weight (0.17 summer, 0.24 winter) overlap (Figure 7).
Variances were homogeneous between seasonal numeric (F = 2.0, P > 0.05) and
weight overlap index (F = 3.84, P > 0.05). Significant differences between sea-
sons were observed in the numeric (F = 457.7, P < 0.01), and weight overlap
(F = 193.7, P < 0.01). All overlaps values (by number and weight) in the two
seasons were significantly lower (P < 0.01).

Discussion

Allen et al. (1995) mentioned that kelp bass is an active predator around kelp
beds and rocky reef habitats, feeding on motile organisms including fish, squid,
octopi and benthic crustaceans, and concluded that a large portion of their prey
were taken from the water column. These results were confirmed for adult kelp
bass inhabiting the kelp beds of Todos Santos Bay, Ensenada, that fed mainly on
fishes (Mendoza-Carranza, 1995). On the other hand, along the southern Califor-
nia coast, kelp bass feed in the mid water and suprabenthos of the kelp beds,

0.6

Ss
uw

=
rs

Morisita’s index
So So
nN) w

SUMMER WINTER

Fig. 7. Seasonal changes in numeric Hf and weight [| diet overlap values between kelp bass and
barred sand bass from Punta Banda estuary (error bars are 95% bootstrap confidence intervals).

114 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

catching small prey as gammarids, caprellids, isopods and mysids (Ebeling and
Bray (1976); Young 1963; Hobson et al. 1981). In Punta Banda estuary, kelp bass
diet was similar, most prey items were small suprabenthic and benthic inverte-
brates (gammarids, decapods, isopods, mollusks, caprellids and mysidaceans).
These preys are abundant in shallow zones of estuaries with eelgrass beds as
Punta Banda Estuary (Ibarra-Obando and Escofet 1987, Ibarra-Obando and Poum-
ian-Tapia 1991, Talley et al. 2000).

Juvenile barred sand bass are also commonly found in eelgrass beds at Alamitos
Bay, California (Valle et al. 1990). In Punta Banda estuary, barred sand bass diet
was dominated by gammarids, although fish, decapods and mollusks were also
important. Most of these items are abundant in eelgrass beds (Ibarra-Obando and
Poumian-Tapia 1991, Levin et al. 1997). Barred sand bass has been classified as
a demersal fish and feed on crustaceans (Roberts et al. 1984). Our results showed
that they also fed heavenly on fishes, some of which, such as pipefish, are eelgrass
dependent.

The presence of eelgrass fragments in the stomach of both species underscore
the importance of these plants as feeding areas. This also was observed for ju-
venile spotted sand bass, Paralabrax maculatofasciatus in Punta Banda estuary
(Mendoza-Carranza 1995; Mendoza-Carranza and Rosales-Casian, 2000).

Seasonal diet pattern in both bass appeared related with changes in size. In
kelp bass, this is reflected in the weight increase of prey as decapods, mollusks,
and fish, mainly. Feeding intensity indicated a significant increase as a product
of increase of prey size. Seasonal patterns in feeding habits for kelp bass were
described by Quast (1968a). Summer diets were characterized by a wide breadth
of prey item while caprellids and clupeiforms fishes dominated in winter. Love
and Ebeling (1978) noted a similar pattern for kelp bass at Santa Barbara kelp
beds.

Feeding habits in barred sand bass were influenced by prey availability and
season (Turner et al. 1969). We believe that differences between seasonal diets
are attributable to change in size; barred sand bass captured in summer were larger
than in winter. This resulted in larger prey items (e.g. decapods, fishes and mol-
lusks) being eaten. Consequently, the feeding intensity was higher in summer.
Roberts et al. (1984) also found that barred sand bass change their diet as they
grow. Changes in size of both bass were related to the differential use of habitats
as eelgrass beds, mud or sandy bottoms in Punta Banda estuary and Todos Santos
bay (Salomé-Sanchéz 1993; Rosales-Casian 1995, 1997a,b; Pintos-Teran 1994;
Mendoza-Carranza 1995).

In Punta Banda estuary, a seasonal diet change of spotted sand bass has been
related to differences in available prey over time, as well as the trophic flexibility
of species (Mendoza-Carranza and Rosales-Casian, 2000). These assertions seem
to also be applicable for kelp bass and barred sand bass.

The interpretation of diet breadth is highly dependent on the variable used to
calculate the indices (Wallace 1981; Hall et al. 1990). A numeric diet breadth
measurement was influenced strongly by few small prey items with high numeric
dominance (Labropoulou and Eleftheriou 1997). In this case, the gammarids cause
low values of niche breadth. On the other hand, biomass tends to overemphasize
some large prey items (Labropoulou and Eleftheriou 1997); contrary to this, we
found that values of weight diet breadth were higher than the numeric diet breadth

FEEDING ECOLOGY OF BASS IN PUNTA BANDA, BAJA CALIFORNIA NS)

in all surveys, caused by the weight distribution among prey items. The weight
distribution was more regular than numeric distribution. The small prey items
were so numerous that they constituted a relatively high biomass.

Overall, the ecological niches of the three species of California basses are
different (Feder et al. 1974) which results in differences in feeding habits. Despite
the low values of niche overlap (<0.60), in Punta Banda estuary, kelp bass and
barred sand bass presented very close trophic affinities feeding on similar prey.
These trophic affinities were likely the result of the generalized morphology of
two species (Roberts et al. 1984) and, the fact that both species were occupying
the same habitats, mainly the eelgrass beds and adjacent areas.

Acknowledgments

This study was founded by Centro de Investigaci6n Cientifica y Educacion
Superior de Ensenada (CICESE) and partially by the Federal Aid to Sportfishing
Act (SFRA-Wallop Breaux) through the Bay Estuarine and Nearshore Ecosystem
Studies (BENES) from the California Department of Fish and Game. Thanks to
Consejo Nacional de Ciencia y Tecnologia (CONACyT) for the scholarship for
MsD studies. Thanks to Gregogy Hammann (Fisheries Ecology, CICESE), Larry
Allen (Department of Biology, California State University, Northridge) and Mil-
ton Love (Marine Science Institute, University of California, Santa Barbara) who
make this project possible. Thanks to Dan Pondella and two anonymous revisers
for manuscript revision and suggestions. Thanks to Vicente Salomé, Marina Mon-
dragon, Pablo Pintos, Alejandro Carrrillo, Idalia Sandoval, and Jorge Rosales-
Vasquez (students); Victor Perez and Cesar Almeda (technicians); Juan Sidon and
Martin Lucero (Boat operators) for their help with the sampling trips and the
laboratory works. Thanks to Zenaido Rosales for repairing the nets.

Literature Cited

Allen, L. G, M. S. Love and J. T. W. Smith. 1995. The life history of the spotted sand bass (Paralabrax
maculatofasciatus) within the southern California bight. CalCOFI rep. 36:193—203.

Cabral, H. N. 2000. Comparative feeding ecology of sympatric Solea solea ans S. senegalis within
the nursery areas of the Tagus estuary, Portugal. J. Fish Biol. 57:1550—1562.

Castro-Longoria, R. and J. M. Grijalva-Chon. 1988. Ictioplancton del Estero Punta Banda, B.C., Mex-
ico durante primavera-verano de 1985. Ciencias Marinas. 14(1):57—79.

Crow, M. E. 1981. Some statistical techniques for analyzing the stomach contents of fish. Fish Food
Habits Studies. Washington Sea Grant Publication. 8—16.

Ebeling, A. W. and R. N. Bray. 1976. Day versus night activity of reef fishes in a kelp forest off Santa
Barbara, California. Fish. Bull. &4(4):703-718.

Efron, B. 1979. Bootstrap methods: another look at the jackknife. Ann. of Stats. 7:1—26.

and R. Tibshirani. 1986. Bootstrap method for standard errors, confidence intervals and others
measurements of statistical accuracy. Stat. Sci. 1:54—77.

Feder, M. H., C. H. Turner and C. Limbaugh. 1974. Observation of fishes associated with kelp beds
in Southern California. Fish. Bull. 160.

Gibson, R. N. and I. A. Ezzi. 1987. Feeding relationships of a demersal fish assemblage on the west
coast of Scotland. J. Fish. Biol. 31:55—69.

Hall, S. J., D. Raffaelli, D. J. Basford, M. R. Robertson and R. Fryer. 1990. The feeding relationship
of the larger fish species in a Scotland sea loch. J. Fish. Biol. 37:775-791.

Hamman, G. and J. A. Rosales-Casian. 1990. Taxonomia y estructura de la comunidad de peces del
Estero Punta Banda y Bahia de Todos Santos, Baja California, Mexico. Cap. 6:153—192. En:
Rosa Vélez J. de la y EK Gonzalez-Farias (eds). Temas de Ocenografia Biol6gica en Mexico.
Ensenada. 337 pp.

116 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

Hobson, E. S., W. N. McFarland, and J. R. Chess. 1981. Crepuscular and nocturnal activities of
California nearshore fishes with consideration of their scotopic visual pigments and the photic
environment. Fish. Bull. 79(1):1—30.

Hurlbert, S. H. 1978. The measurement of niche overlap and some relatives. Ecology. 59:67—77.

Hyslop, E. J. 1980. Stomach contents analysis-a review of methods and their application. J. Fish Biol.
17:411—429.

Ibarra-Obando, S. E. and A. Escofet. 1987. Industrial development effects on the ecology of a Pacific
Mexican estuary. Environ. Conserv. 14(2):135—141.

and M. Poumian-Tapia. 1991. The effects of tidal exclusion on salt march vegetation in Baja

California, Mexico. Wetlands Ecol. Manage. 1:131—148.

and M. Poumian-Tapia. 1992. The saltmarsh vegetation of Punta Banda estuary, Baja Cali-
fornia, México. In: Coastal plant communities of Latin America. U. Seeliger, ed. San Diego,
Calif.: Academic Press, pp. 201-211.

Krebs, C. J. 1989. Ecological Methodology. New York. Harper & Row, 654 pp.

Labropoulou, M. and A. Eleftheriou. 1997. The foraging ecology of two pairs of congeneric demersal
fish species: importance of morphological characteristics in prey selection. J. Fish Biol. 50:
324-340.

Levin, P. S., R. Petrik and J. Malone. 1997. Interactive effects of habitat selection, food supply and
predation on recruitment of an estuarine fish. Oecologia 112:55—63.

Love, M. S. and A. W. Ebeling. 1978. Food and habitat of three switch-feeding fishes in the kelp
forest off Santa Barbara, California. Fish. Bull. 76(1):257—271.

Mendoza-Carranza, M. 1995. Descripci6n y comparacion de la dietas de Paralabrax maculatofascia-
tus, P. clathratus y P. nebulifer en el Estero de Punta Banda y la Bahia de Todos Santos,
Ensenada, B.C. México. M.Sc. thesis, Ecologia Marina, CICESE. 64 pp.

and J. A. Rosales-Casian. 2000. The feeding habits of spotted sand bass (Paralabrax macu-
latofasciatus) in Punta Banda estuary, Ensenada, Baja California, Mexico. CalCOFI Rep. 41:
194—200.

Miller, D. J. and R. N. Lea. 1972. Guide to the coastal marine fishes of California. Cal. Dept. Fish
Game. Fish Bull. 157:235 pp.

Navarro-Mendoza, M. 1985. Ecologia tréfica de la comunidad ictica en el Estero Punta Banda, En-
senada, Mexico. M.Sc. thesis, Ecologia Marina, CICESE. 185 pp.

Ono, D. S. 1992. Sand basses. In: California’s living marine resources and their utilization. W. S. Leet,
C. M. Dewees, and C. W. Haugen eds. Sea Grant Ext. Publ. UCSGEP-92-12, 257 pp.

Pinkas, L., M. S. Oliphant and I. L. K. Iverson. 1971. Food habits of albacore, bluefin tuna and bonito
in California waters. Calif. Depart. of Fish and Game, Fish Bull. 152:105 pp.

Pintos-Teran, P. A. 1994. Estructura poblacional y crecimiento de la cabrilla de arena Paralabrax
nebulifer (Girard) en la Bahia de Todos Santos y el Estero de Punta Banda. Bachelor Thesis.
Facultad de Ciencias Marinas, Universidad Autonoma de Baja California, Ensenada. 70 pp.

Quast, J. C. 1968. Observations on the food and biology of the kelp-bass Paralabrax clathratus. Calif.
Dept. Fish and Game, Fish. Bull. 139:81—108.

Roberts, D. A., E. E. DeMartini and K. M. Plummer. 1984. The feeding habits of juvenile-small adult
barred sand bass (Paralabrax nebulifer) in nearshore waters off northern San Diego county.
CalCOFI Reports. 25:105—111.

Rodriguez-Medrano, M del C. 1993. Descripcion y analisis de la pesca deportiva en Bahia Todos
Santos, Ensenada, B. C. M.Sc. thesis, Ecologia Marina, CICESE. 88 pp.

Rosales-Casian, J. A. and M. G. Hammann. 1993. The Bahia de Todos Santos and Estero de Punta
Banda, Baja California, México: a BENES project for the study of coastal fishes. Report of
activities and preliminary results, June 1992 to May 1993. Attachment C. In: Allen, L. G. 1993.
BENES, Bay Estuarine and Nearshore Ecosystem Studies. Annual progress report for fiscal
year 1992-1993. Prepared for the Calif. Dep. Fish. Game. 122 pp.

. 1995. Ciclo de vida de la cabrilla sargacera (Paralabrax clthratus GIRARD), migracion y

transporte de biomasa de sus juveniles en la Bahia de Todos Santos y el Estero de Punta Banda,

B.C. México. Comunicaciones Académicas, Serie Ecologia. CICESE CTECA9501. 14 pp.

. 1997a. Inshore soft-bottom fishes of two coastal lagoons on the northern Pacific coast of Baja

California. CalCOFI Rep. 38:180—192.

. 1997b. Estructura de la comunidad de peces y el uso de los ambientes de bahias, lagunas

FEEDING ECOLOGY OF BASS IN PUNTA BANDA, BAJA CALIFORNIA LL

y costa abierta en el Pacifico norte de Baja Caliofnia. PhD thesis, Ecologia Marina, CICESE.
201 ip:

Salomé-Sanchez, J. V. 1993. Composicion, estructura y aspectos biologicos de la cabrilla sargacera
(Paralabrax clathratus, Girard) en la Bahia de Todos Santos y en el Estero de Punta Banda,
B.C., México, durante mayo a octubre de 1992. Bachelor Thesis. Facultad de Ciencias Marinas,
Universidad Autonoma de Baja California, Ensenada. 53 pp.

Sokal, R. R. and E J. Rohlf. 1981. Biometry. W. H. Freeman and Company. 2nd edition San Francisco,
USA. 858 p.

Talley, T. S., P K. Dayton and S. E. Ibarra-Obando. 2000. Tidal flat macrofaunal communities and
their associated environments in estuaries of southern California and northern Baja California,
Mexico. Estuaries 23(1):97—114.

Turner, C. H., E. E. Ebert and R. R. Given. 1969. Man-made reef ecology. Calif. Dept. Fish Game.
Bull. 146:221 pp.

Valle, C. EK, J. W. O’Brien and K. B. Wiese. 1990. Differentiation habitat use by California halibut,
Paralichthys californicus, barred sand bass, Paralabrax nebulifer, and other juvenile fishes in
Alamitos Bay, California. Fish. Bull. 97:646—660.

Wallace, H. 1981. An assessment of diet overlap indexes. Trans. of Am. Fish. Sco. 110:72—76.

and J. S. Ramsay. 1983. Reliability in measuring diet overlap. Can. Jour. Fish Aquat. Sci. 40:
347-351.

Young, P. H. 1963. The kelp-bass (Paralabrax clathratus) and its fisheries 1947-1957. Calif. Dept.
Fish. and Game. 122. 67 pp.

Zar, J. H. 1984. Biostatistical analysis. 2nd Edition. Prentice Hall International, Inc. Englewood Cliffs,
New Jersey. 718 pp.

Accepted for publication 7 March 2002.

Bull. Southern California Acad. Sci.
101(3), 2002, pp. 118-130
© Southern California Academy of Sciences, 2002

Helminths of the Bullfrog, Rana catesbeiana (Ranidae), in
California with Revisions to the California Anuran Helminth List

Stephen R. Goldberg

Department of Biology, Whittier College, Whittier, California 90608,
e-mail: sgoldberg @ whittier.edu

Charles R. Bursey

Department of Biology, Pennsylvania State University, Shenango Campus,
Sharon, PA 16146, e-mail: cxb13@psu.edu

Abstract.—Thirty-one bullfrogs, Rana catesbeiana, from northern California were
examined for helminths. Gravid individuals representing three species of Trema-
toda, Glypthelmins quieta, Haematoloechus longiplexus and Megalodiscus tem-
peratus; one species of Cestoda, Ophiotaenia magna; and three species of Nem-
atoda, Cosmocercoides variabilis, Falcaustra catesbeianae and Oswaldocruzia
pipiens were found. Larvae representing three species of Nematoda, Contracae-
cum sp., Eustrongylides sp., and Physaloptera sp. were also found. Rana cates-
beiana is parasitized by generalist helminths that occur in other frogs and have
previously been found in R. catesbeiana in other parts of North America. This is
the first report of Falcaustra catesbeianae, Contracaecum sp. and Eustrongylides
sp. from California anurans. The helminth host list for California anurans is re-
vised.

The bullfrog, Rana catesbeiana, was first described from a collection taken in
the vicinity of Charleston, South Carolina (Shaw, 1802). The original range cov-
ered most of eastern North America from the mouth of the Pecos River, Texas
through the Panhandles of Texas and Oklahoma, extreme western Kansas, Ne-
braska and Minnesota, eastward to Maine and the northern half of Florida (Wright
and Wright 1995). Subsequently, the bullfrog was introduced into each of the
western states as well as Mexico and British Columbia, Canada (Stebbins 1985).
In California, bullfrogs were first introduced in 1896 (Heard 1904) for human
food after populations of native frogs, particularly the red-legged frog, Rana au-
rora, were overharvested (Jennings and Hayes 1985). Introductions and subse-
quent range expansions of the bullfrog have coincided with declines of native
ranid frogs in western North America which has in turn generated interest in frog
population ecology and competition (Kiesecker and Blaustein 1997; Kupferberg
1997; Lawler et al. 1999). However, little attention has been given to helminths
of introduced frogs. To our knowledge, there are four reports of helminths in
California bullfrogs (Ingles 1936; Nicol et al. 1985; Shields 1987; Wootton et al.
1993). Helminths of the bullfrog in North America have been summarized by
Andrews et al. (1992). Additional helminths are listed in Bursey and DeWolf
(1998), Goldberg et al. (1998) and McAlpine and Burt (1998). The purpose of
this paper is to report additional helminths of California bullfrogs and to revise
the helminth list for California anurans.

118

HELMINTHS OF THE BULLFROG IN CALIFORNIA LS

Methods

Thirty-one bullfrogs collected in 1997 and 1998 from northern California were
examined for helminths. All frogs were deposited in the herpetology collection
of the Natural History Museum of Los Angeles County (LACM) after examina-
tion. Sixteen frogs (LACM 144342-144357) were from Upper Searsville Lake,
Jasper Ridge Biological Preserve, Woodside, San Mateo County (37°30'N,
122°30'W); 15 frogs (LACM 146746-146751, 146753, 146754, 146756-146762)
were from sites between Uvas and Calero Reservoirs, Santa Clara County
(37°05'N, 121°45'W). The frogs were initially fixed in 10% formalin and pre-
served in 70% ethanol. The body cavity was opened by a longitudinal incision
from throat to pelvis and the gastrointestinal tract, lungs and urinary bladder were
removed. Each organ was opened and examined for helminths under a dissecting
microscope. The surface of the liver and the body cavity were also searched.
Nematodes were placed on a microscope slide and cleared in glycerine. A cov-
erslip was added to the slide and the nematode was identified using a compound
microscope. Cestodes and trematodes were rehydrated, stained in hematoxylin,
dehydrated in a series of graded ethanols, cleared in xylene, mounted on a glass
slide in Canada balsam and identified using a compound microscope.

Three similarity indices were calculated in order to compare the R. catesbeiana
helminths from San Mateo and Santa Clara Counties. The Jaccard coefficient is
based on species presence in a community and ranges from O (no species in
common) to 1.0 (all species in common); Morisita’s index considers number of
species, number of individuals, and proportion of the total represented by each
species and ranges from O (no similarity) to 1.0 Gdentical); percent similarity is
based on species abundance and ranges from 0 (no similarity) to 100 (same spe-
cies found in both communities at similar abundances) (Brower et al. 1997).

Results

Gravid individuals of three species of Trematoda, Glypthelmins quieta (Staf-
ford, 1900), Haematoloechus longiplexus Stafford 1902, Megalodiscus temperatus
(Stafford, 1905); one species of Cestoda, Ophiotaenia magna Hannum, 1925; and
three species of Nematoda, Cosmocercoides variabilis (Harwood, 1930), Fal-
caustra catesbeianae Walton, 1929, Oswaldocruzia pipiens Walton, 1929, were
found. Larvae representing three species of Nematoda, Contracaecum sp., Eus-
trongylides sp., and Physaloptera sp. were also found. Prevalence (percent of
sample infected) and mean intensity (mean number of helminths per infected frog
+ 1 SD) by helminth species are given in Table 1.

The helminths exhibited site specific infections: Glypthelmins quieta, Ophio-
taenia magna, Cosmocercoides variabilis and Oswaldocruzia pipiens were found
in the small intestine, Megalodiscus temperatus and Falcaustra catesbeianae in
the large intestine, and Haematoloechus longiplexus in the lungs. Larvae of Con-
tracaecum sp., and Eustrongylides sp. were found in cysts within the body cavity
and most often attached to the mesenteries; larvae of Physaloptera sp. were found
within the lumen of the stomach. In no cases did two parasite species occupy the
Same site in a single host.

Selected helminths were deposited in the United States National Parasite Col-
lection, USNPC, Beltsville, Maryland 20705 as: Glypthelmins quieta (91248),

120 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

Table 1. Prevalence (as %), mean intensity + 1 SD, and range for helminths from Rana catesbeiana
from San Mateo and Santa Clara Counties, California; n = number of hosts examined.

San Mateo County Santa Clara County
n= 16 n= 15

(SVL = 109 mm += 18 mm SD) (SVL = 153 mm = 17 mm SD)

Preva- Mean Preva- Mean

lence intensity Range lence intensity Range
Glypthelmins quieta 6 | — i) 12 ==
Haematoloechus longiplexus 56 AES pte Sed 1-17 49 307 el 1-17
Megalodiscus temperatus 56 OP) 5) —— —— —
Ophiotaenia magna — — a 20 LF ENO) —
Cosmocercoides variabilis — — — 7 2, —
Falcaustra catesbeianae 50 AB F336 1-12 — — —
Oswaldocruzia pipiens — — 7 6 =
Contracaecum sp. (larvae) 38 Dae eA 1-5 — — —
Eustrongylides sp. (larvae) — — — 20 lige 0) —
Physaloptera sp. (larvae) — — — 20 D7) AMES 1-4

Haematoloechus longiplexus (91244), Megalodiscus temperatus (91245), Ophio-
taenia magna (91249), Cosmocercoides variabilis (91250), Falcaustra catesbei-
anae (91246), Oswaldocruzia pipiens (91251), Contracaecum sp. (91247), Eus-
trongylides sp. (91252), Physaloptera sp. (91253).

Discussion

All helminths found in this study have previously been reported from Rana
catesbeiana in other parts of its range as well as from other ranids (Dyer 1991;
Andrews et al. 1992). However, this is the first report of Falcaustra catesbeianae,
Contracaecum sp. (larvae) and Eustrongylides sp. (larvae) from California an-
urans (Table 2).

Glypthelmins quieta, Haematoloechus longiplexus and Megalodiscus tempera-
tus are common trematode parasites of North American frogs (Smyth and Smyth
1980). These three species require a molluscan first intermediate host. After re-
lease from the molluscan host, cercariae of Glypthelmins quieta and Megalodiscus
temperatus penetrate the skin of anurans and encyst beneath the epidermis. In-
fection occurs when a frog ingests its own cast skin after molting. Cercariae of
Haematoloechus longiplexus penetrate and encyst in naiads of dragonflies; infec-
tion occurs through ingestion of dragonflies (Smyth and Smyth 1980). The host
list for Glypthelmins quieta includes five genera of anurans, Acris, Bufo, Hyla,
Pseudacris and Rana; for Haematoloechus longiplexus, two genera, Bufo and
Rana; for Megalodiscus temperatus, four genera of anurans, Bufo, Hyla, Pseu-
dacris, and Rana, five genera of Caudata, Ambystoma, Amphiuma, Desmognathus,
Notophthalmus and Pseudotriton, and one genus of Serpentes, Coluber (Parker
1941; Catalano et al. 1982; Prudhoe and Bray 1982).

There is some confusion surrounding the identity of North American ranid
proteocephalid cestodes; four have been reported, namely, Ophiotaenia magna,
Ophiotaenia saphena Osler, 1931, Crepidobothrium olor Ingles, 1936 and Ophio-
taenia gracilis Jones, Cheng and Gillespie, 1958. Brooks (1978) discussed mor-
phological characteristics of these species and concluded no significant morpho-

120

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HELMINTHS OF THE BULLFROG IN CALIFORNIA 127

logical differences existed between them. He did not place them in synonymy but
assigned all to Proteocephalus. More recently, Schmidt (1986) assigned these
species to Ophiotaenia. Since it is not possible to distinguish these four species
and because we can find no difference between individuals collected in California
and Ohio (see Bursey and DeWolf 1998), we have assigned our specimens to
Ophiotaenia magna which has priority. In addition, we have referred all California
ranid proteocephalids to Ophiotaenia magna (Table 2).

Cosmocercoides variabilis, Falcaustra catesbeianae and Oswaldocruzia pi-
piens are common nematode parasites of North American frogs (Baker 1987).
Like the trematodes found in this study, these nematodes are generalists, 1.e.,
found in more than one host. However, some uncertainty exists for hosts of North
American species of Cosmocercoides. Cosmocercoides variabilis, originally de-
scribed as Oxysomatium variabilis by Harwood (1930) from Bufo valliceps col-
lected at Houston, Texas was considered a synonym of the molluscan parasite
Cosmocercoides dukae by Ogren (1953, 1959) who presumed that amphibians
acquired C. dukae infections by ingesting infected molluscs. Cosmocercoides du-
kae was first described as Cosmocerca dukae by Holl (1928) from Triturus viri-
descens collected in North Carolina. Wilkie (1930) established the genus Cos-
mocercoides, and Travassos (1931) included both C. dukae and C. variabilis in
his monograph on the Cosmocercidae. Vanderburgh and Anderson (1987) dem-
onstrated that these two species of Cosmocercoides are distinct. The major dif-
ference between the two species is the number of rosette papillae of the male; C.
dukae with 12 pairs; C. variabilis with 14 to 20. Specimens collected in this study
exhibited 16—18 rosette papillae. The host list for C. variabilis includes the five
genera of anurans, Bufo, Gastrophryne, Hyla, Pseudacris, Rana, two genera of
Caudata, Ambystoma, Notophthalmus; two genera of lizards, Scincella, Ophisau-
rus; three of snakes, Heterodon, Micrurus, Storeria; and one of tortoises, Ter-
rapene (Baker 1987). Ingles (1936) reported C. dukae from Taricha torosa, Rana
aurora and Bufo boreas from California but illustrated 16 papillae and for this
reason we have referred his specimens to Cosmocercoides variabilis (Table 2).
Falcaustra catesbeianae has been reported from four genera of Anura, namely,
Gastrophryne, Hyla, Pseudacris, Rana, and two genera of Caudata, Siren and
Typhlotriton (Baker 1987). All North American specimens of the genus Oswal-
docruzia have been referred to O. pipiens by Baker (1977). This species is widely
distributed in North America and has been reported from six genera of anurans,
Acris, Bufo, Hyla, Pseudacris, Rana, Scaphiopus; three of Caudata, Desmogna-
thus, Eurycea, Plethodon, seven genera of lizards, Anolis, Eumeces, Elgaria, Ger-
rhonotus, Heloderma, Sceloporus, Scincella; and one of tortoises, Terrapene
(Baker 1987; Goldberg and Bursey 1991).

Three species of nematodes not reaching maturity in frogs were present: Con-
tracaecum sp., Eustrongylides sp. and Physaloptera sp. Species of these genera
require intermediate hosts: Contracaecum, aquatic invertebrates; Eustrongylides,
aquatic oligochaetes; Physaloptera, terrestrial insects (Anderson 2000). The de-
finitive hosts of species of Contracaecum are piscivorous birds and aquatic mam-
mals, species of Eustrongylides are limited to piscivorous birds, and species of
Physaloptera parasitize mammals, birds and reptiles (Anderson 2000). Because
individuals of Contracaecum and Eustrongylides were found in cysts, the possi-
bility of Rana catesbeiana as a paratenic host must be considered. The absence

128 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

of Physaloptera in cysts suggests that they are taken with insect prey but cannot
establish infection and are soon excreted.

Interestingly, of the ten species of helminths found in this study, only two
trematodes, Glypthelmins quieta and Haematoloechus longiplexus were found at
both locations of bullfrog collections. The 16 bullfrogs from San Mateo harbored
94 individuals representing 5 helminth species; 15 bullfrogs from Santa Clara
harbored 67 individuals representing seven helminth species. The calculated re-
sults for Jaccard coefficient, Morisita’s index and percent similarity were 0.2, 0.7,
47.9, respectively, indicating that the helminth communities harbored by the two
bullfrog populations were not similar in structure. Other studies of California
anurans (see Koller and Gaudin 1977; Goldberg and Bursey 2001a, 2001b) from
multiple localities have reported similar results, 1.e., spotty distribution of hel-
minths for a particular host species.

The anuran helminths listed in Table | are generalists in that they are capable
of infecting a number of hosts. Thus, it is possible that a particular host is un-
important; infection in a particular host may fluctuate from location to location,
but the helminth population maintains an overall presence. Given the earlier in-
troduction of the bullfrog to California and the later helminthological surveys
(Table 2), it is not possible to determine whether bullfrogs acquired these hel-
minths in California or transported them into the state. Neither is it possible to
gauge the breadth of helminth infection for California anurans because only 8
(35%) of the 23 species of anurans known to occur in California (Stebbins 1985)
have been examined for helminths. Examination of additional California anuran
species must occur before the helminth community of these hosts can be assessed.

Acknowledgment

Pieter T. J. Johnson (Stanford University) collected the sample of Rana cates-
beiana.

Literature Cited

Anderson, R. C. 2000. Nematode Parasites of Vertebrates. Their Development and Transmission. 2nd
edition, CABI Publishing, CAB International. Wallingford, UK, xx + 650 pp.

Andrews, K. D., R. L. Lampley, M. A. Gillman, D. T. Corey, S. R. Ballard, M. J. Blasczyk, and W.
G. Dyer. 1992. Helminths of Rana catesbeiana in southern [linois with a checklist of helminths
in bullfrogs of North America. Trans. III. St. Acad. Sci., 85:147—172.

Baker, M. R. 1977. Redescription of Oswaldocruzia pipiens Walton, 1929 (Nematoda: Trichostron-
gylidae) from amphibians of eastern North America. Can. J. Zool., 55:104—109.

. 1987. Synopsis of the Nematoda parasitic in amphibians and reptiles. Mem. Univ. Newfound-
land, Occas. Pap. Biol., 11:1—325.
Brooks, D. R. 1978. Systematic status of proteocephalid cestodes from reptiles and amphibians in
North America with descriptions of three new species. Proc. Helm. Soc. Wash., 45:1—28.
Brower, J. E., J. H. Zar and C. N. von Ende. 1997. Field and Laboratory Methods for General Ecology,
4th edition, WCB McGraw-Hill, Boston, Massachusetts, xi + 273 pp.

Bursey, C. R., and W. E DeWolf II. 1998. Helminths of the frogs, Rana catesbeiana, Rana clamitans,
and Rana palustris, from Coshocton County, Ohio. Ohio J. Sci., 98:28—29.

Catalano, P. A., A. M. White, and F J. Etges. 1982. Helminths of the salamanders Gyrinophilus
porphyriticus, Pseudotriton ruber, and Pseudotriton montanus (Caudata: Plethodontidae) from
Ohio. Ohio J. Sci., 82:120—128.

Cort, W. W. 1919. A new distome from Rana aurora. Univ. Calif. Publ. Zool., 19:283—298.

Dailey, M. D. and S. R. Goldberg. 2000. Langeronia burseyi sp. n. (Trematoda: Lecithodendriidae)

HELMINTHS OF THE BULLFROG IN CALIFORNIA [29

from the California treefrog, Hyla cadaverina (Anura; Hylidae), with revision of the genus
Langeronia Caballero and Bravo-Hollis, 1949. Comp. Parasitol., 67:165—168.

Dyer, W. G. 1991. Helminth parasites of amphibians from Illinois and adjacent midwestern states.
Trans. Ill. St. Acad. Sci., 84:125—143.

Goldberg, S. R., and C. R. Bursey. 1991. Gastrointestinal helminths of the reticulate Gila monster,
Heloderma suspectum (Sauria: Helodermatidae). J. Helm. Soc. Wash., 58:146—149.

, and . 2001a. Helminths of the California treefrog, Hyla cadaverina (Hylidae), from

southern California. Bull. So. Calif. Acad. Sci., 100:117—122.

, and . 2001b. Persistence of the nematode, Oswaldocruzia pipiens (Molineidae), in the
Pacific treefrog, Hyla regilla (Hylidae), from California. Bull. So. Calif. Acad. Sci., 100:44—
50.

. , and H. Cheam. 1998. Helminths of two native frog species (Rana chiricahuensis,

Rana yavapaiensis) and one introduced frog species (Rana catesbeiana) (Ranidae) from Ari-

zona. J. Parasitol., 84:175—177.

i , and S. Hernandez. 1999. Helminths of the western toad, Bufo boreas (Bufonidae)
from southern California. Bull. So. Calif. Acad. Sci., 98:39—44.

Harwood, P. D. 1930. A new species of Oxysomatium (Nematoda) with some remarks on the genera
Oxysomatium and Aplectana, and observations on the life history. J. Parasitol., 17:61—73.

Heard, M. 1904. A california frog ranch. Out West, 21:20—27.

Holl, E J. 1928. Two new nematode parasites. J. Elisha Mitchell Sci. Soc., 43:184—-186.

Ingles, L. G. 1932a. Cephalogonimus brevicirrus, a new species of trematode from the intestine of
Rana aurora from California. Univ. Calif. Publ. Zool., 37:203—210.

. 1932b. Four new species of Haematoloechus (Trematoda) from Rana aurora draytoni from

California. Univ. Calif. Publ. Zool., 37:189—201.

. 1933. Studies on the structure and life-history of Ostiolum oxyorchis (Ingles) from the Cal-

ifornia red-legged frog Rana aurora draytoni. Univ. Calif. Publ. Zool., 39:135—162.

. 1936. Worm parasites of California Amphibia. Trans. Am. Micro. Soc., 55:73—92.

, and C. I. Langston. 1933. A new species of bladder fluke from California frogs. Trans. Am.
Micro. Soc., 52:243—245.

Jennings, M. R., and M. P. Hayes. 1985. Pre-1900 overharvest of California red-legged frogs (Rana
aurora draytonii): the inducement for bullfrog (Rana catesbeiana) introduction. Herpetologica,
41:94—103.

Johnson, P. T. J.. K. B. Lunde, E. G. Ritchie and A. E. Launer. 1999. The effect of trematode infection
on amphibian limb development and survivorship. Science 284:802—804.

Kiesecker, J. M., and A. R. Blaustein. 1997. Population differences in responses of red-legged frogs
(Rana aurora) to introduced bullfrogs. Ecology, 78:1752—1760.

Koller, R. L. and A. J. Gaudin. 1977. An analysis of helminth infections in Bufo boreas (Amphibia:
Bufonidae) and Hyla regilla (Amphibia: Hylidae) in Southern California. Southwest. Nat., 21:
503-509.

Kupferberg, S. J. 1997. Bullfrog (Rana catesbeiana) invasion of a California river: the role of larval
competition. Ecology, 78:1736—1751.

Lawler, S. P., D. Dritz, T. Strange, and M. Holyoak. 1999. Effects of introduced mosquitofish and
bullfrogs on the threatened California red-legged frog. Conservation Biol., 13:613—622.

Lehmann, D. L. 1960. Some parasites of central California amphibians. J. Parasitol., 46:10.

McAlpine, D. F and M. D. B. Burt. 1998. Helminths of bullfrogs, Rana catesbeiana, green frogs, R.
clamitans, and leopard frogs, R. pipiens in New Brunswick. Can. Field Nat., 112:50—68.

Nicol, J. T., R. Demaree, Jr., and D. M. Wootton. 1985. Levinseniella (Monarrhenos) ophidea sp. n.
(Trematoda: Microphallidae) from the western garter snake, Thamnophis elegans and the bull-
frog, Rana catesbeiana. Proc. Helm. Soc. Wash., 52:180—183.

Ogren, R. E. 1953. A contribution to the life cycle of Cosmocercoides in snails (Nematoda: Cosmo-
cercidae). Trans. Am. Micro. Soc., 72:87—91.

. 1959. The nematode Cosmocercoides dukae as a parasite of the slug. Proc. Penn. Acad. Sci.,
33:236-241.

Parker, M. V. 1941. The trematode parasites from a collection of amphibians and reptiles. J. Tenn.
Acad. Sci., 16:27—45.

Prudhoe, S., and R. A. Bray. 1982. Platyhelminth parasites of the Amphibia. British Museum (Natural
History), Oxford University Press, Oxford, U.K. 217 pp + 4 microfiche.

130 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

Schmidt, G. D. 1986. CRC Handbook of Tapeworm Identification. CRC Press, Inc., Boca Raton,
Florida, 675 pp.

Shaw, G. 1802. General Zoology or Systematic Natural History. Volume III. Amphibia. Published for
the author by Thomas Davison, London. In two parts, as follows: I: Engraved title page, vi (2),
312 pp, 86 plates. II: Engraved title page, vi, (1), 313-615 pp, 54 plates.

Shields, J. D. 1987. Pathology and mortality of the lung fluke Haematoloechus longiplexus (Trema-
toda) in Rana catesbeiana. J. Parasitol., 73:1005—1013.

Smyth, J. D., and M. M. Smyth. 1980. Frogs as Host-Parasite Systems. I. An Introduction to Parasi-
tology through the Parasites of Rana temporaria, R. esculenta and R. pipiens. Macmillan Press,
Ltd., London, UK. ix.+ 112 \pp.

Stebbins, R. C. 1985. A Field Guide to Western Reptiles and Amphibians. Houghton Mifflin Company,
Boston, Massachusetts, xiv + 336 pp.

Travassos, L. 1931. Pesquizas helminthologicas realizadas em Hamburgo. IX. Ensaio monographico
da familia Cosmocercidae Trav., 1925 (Nematoda). Mem. Instit. Oswaldo Cruz, 25:235—298.

Vanderburgh, D. J., and R. C. Anderson. 1987. The relationship between nematodes of the genus
Cosmocercoides Wilkie, 1930 (Nematoda: Cosmocercoidea) in toads (Bufo americanus) and
slugs (Deroceras laeve). Can. J. Zool., 65:1650—1661.

Walton, A. C. 1941. Notes on some helminths from California amphibia. Trans. Am. Micro. Soc., 60:
53-57.

Wilkie, J. S. 1930. Some parasitic nematodes from Japanese Amphibia. Annals and Mag. Natur. Hist.,
Ser. 10, 6:606—614.

Wootton, D. M., K. A. Ryan, R. S. Demaree, and R. L. Critchfield. 1993. A new species of Gyro-
dactylus (Monogenea: Monopisthocotylea) on tadpoles of Rana catesbeiana from California,
U.S.A. Trans. Am. Micro. Soc., 112:230—233.

Wright, A. H., and A. A. Wright. 1995. Handbook of Frogs and Toads of the United States and Canada.
Comstock Publishing Associates, Cornell Univ. Press, Ithaca, New York, xxii + 640 pp.

Accepted for publication 11 October 2001.

Bull. Southern California Acad. Sci.
101(3), 2002, pp. 131—136
© Southern California Academy of Sciences, 2002

New Records of Mammals on Small Islands in the Central Gulf of
California, México

Paul Stapp

Department of Environmental Science and Policy, University of California,
Davis, California 95616

The rich biota of islands in the Gulf of California has attracted the efforts of
naturalists and research biologists for nearly a century (Case and Cody 1983).
Mammals are among the better-studied groups and have been the focus of bio-
geographical and evolutionary research (e.g., Burt 1932; Huey 1964; Banks 1967;
Lawlor 1971, 1983). Much of this work focused on fauna of large islands in the
southern Gulf and Midriff region (e.g., Vaughan and Schwartz 1960; Gill 1981;
Smith 1992), whereas less is known of the distribution of mammals on the dozens
of small islands that surround the Baja peninsula. These small islands may be
particularly important for studies of island biogeography because island area
strongly influences resource availability and the probability of extinction and col-
onization of insular populations (MacArthur and Wilson 1967; Whittaker 1998).
Here, I provide new records of the distribution of mammals on a series of small
islands in the central Gulf of California. These data were collected as part of a
larger research effort aimed at understanding the dynamics of island food webs
(Polis and Hurd 1996; Polis et al. 1997; Stapp et al. 1999).

Between 1997 and 2000, I surveyed for the presence of rodents at 27 sites on
18 different islands in the vicinity of Bahia de los Angeles, Baja California,
México (28°55’ N latitude, 113°30' W longitude), as well as in 14 locations on
the adjacent peninsula within a 30-km radius of the town of Bahia de los Angeles.
The islands are extremely rocky and, except for a few perennials (Atriplex bar-
clayana, Opuntia spp., Viscainoa geniculata, Pachycereus pringlei), have little
vegetation. Sherman live traps were set in rectangular grids consisting of 24—54
traps, with one side of the grid near shore and extending inland for 125—200 m.
On smaller islands or those whose terrain limited access (e.g., Mitlan and Blanca),
traps were set in pairs of transects originating at the shore. Near-shore traps were
usually set in coastal vegetation (Salicornia subterminalis, Sueda moquinii, Fran-
kenia palmeri) associated with dunes or beach cobble, which then graded into
more gravelly and rocky soils and desert scrub vegetation farther inland. Several
islands, including those used by roosting and nesting seabirds, however, were
essentially piles of bare rock and had little permanent vegetation.

Trapping sessions typically lasted 2 or 3 consecutive nights. Traps were baited
with peanut butter and oats and closed during the day to reduce mortality from
heat and ants. I weighed and measured all rodents captured, and marked each
with an ear-tag or Sharpie® permanent marker before releasing it at its capture
location. I visited island and mainland sites during 11 separate trips to the region
between 1997 and 2000.

Twelve species (Chaetodipus baileyi, C. spinatus, C. arenarius, C. formosus,
Perognathus longimembris, Dipodomys merriami, Neotoma lepida, Peromyscus

131

SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

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RODENTS ON GULF OF CALIFORNIA ISLANDS

Gulf of
California

a oat

+\ Bahia de los
Angeles

134 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

maniculatus, P. eremicus, P. crinitus, Ammospermophilus leucurus) were captured
in a total of >6000 trap-nights (TN), but only two species were recorded on
islands. These were identified as P. maniculatus and C. baileyi based on pelage
characteristics and comparisons of morphological measurements (taken from live
individuals) to those of individuals captured on the adjacent mainland (Table 1).
Lawlor (1971) also reported P. maniculatus and Perognathus (= Chaetodipus)
baileyi from Smith, the largest island (9.13 km?) in Bahia de los Angeles. Both
species are relatively uncommon on islands in the Gulf; the only other records of
insular C. baileyi are from Tibur6n and Monserrate, and of P. maniculatus, from
Willard in Bahia de San Luis Gonzaga, some 120 km north (Lawlor 1983). In
contrast, C. spinatus and P. eremicus and their islands derivatives inhabit nearby
Angel de la Guarda and its satellite islands, as well as several islands in the San
Lorenzo chain farther south (Gill 1981; Lawlor 1983), but were not found on any
of the islands I surveyed. Because our Mexican research permits only permitted
live-trapping, I did not collect voucher specimens or attempt to determine the
subspecies status of insular populations.

P. maniculatus was more widespread among islands than C. baileyi, inhabiting
nine of the 14 islands in Bahia de los Angeles and one of the four islands in and
near Bahia las Animas (Fig. 1). C. baileyi was captured on only three islands, all
of which were also inhabited by P. maniculatus. No mice were caught on any of
the other eight islands surveyed, all of which were very small (<0.05 km/?; Polis
et al. 1997). Although trapping effort was relatively low on these islands (14-40
TN; Fig. 1) and they were only trapped on one occasion, a similar effort was
sufficient to document the presence of rodents on other islands.

Many of the islands inhabited by P. maniculatus were small (<O.2 km/? in area)
and located relatively far (>2.5 km) from the peninsula (Fig. 1), although most
of these were <1.5 km from larger islands (Smith, Ventana) that may act as source
populations. Four of the islands lacking mice were larger than the smallest island
where P. maniculatus was captured (Blanca; 0.03 km?). These islands were not
especially isolated, but their surfaces tended to be more solid and less friable, and
with fewer talus piles, which may not provide enough cover to support rodent
populations consistently. The presence of C. baileyi on Mitlan, which is <200 m
from Smith, was not surprising, but Pata, the other small island inhabited by C.
baileyi, is much more isolated from potential source populations (=2.5 km from
both Smith and the peninsula), and thus may have been occupied by C. baileyi
since submergence in the late Pleistocene (Gastil et al. 1983). To my knowledge,
this is the smallest island (0.18 km?) known be inhabited by pocket mice (Chae-

ee

Fig. 1. Map of Bahia de los Angeles, Baja California, México, showing the location of Gulf of
California islands surveyed for rodents. Peromyscus maniculatus was captured on ten islands (island
number, total trapping effort during 1997-2000): Coronadito (1, 108 TN); Smith (2, 2070 TN); Mitlan
(3, 220 TN); Piojo (4, 180 TN); Pata (5, 468 TN); Bota (6, 264 TN); Flecha (8, 304 TN); Ventana
(11, 558 TN); Cabeza de Caballo (12, 270 TN); and Blanca (16, 108 TN). Chaetodipus baileyi was
only captured on Smith (2), Mitlan (3), and Pata (5). Islands where no mice were captured: Jorobado
(7, 36 TN); Llave (9, 40 TN); Cerraja (10, 36 TN); Gemelos West and East (13-14, 36 TN each);
Pescador (15, 36 !N); and Las Animas Norte and Sur (17-18, 14 TN each). Locations of 12 of the
14 mainland trapping sites are denoted with an ‘‘X’’; the other two sites were 20 km inland.

RODENTS ON GULF OF CALIFORNIA ISLANDS 135

todipus, Perognathus), which are granivorous and tend to be restricted to larger
islands with high plant diversity and, hence, consistent seed production (Lawlor
1983). Omnivores like Peromyscus are more common on Gulf islands and else-
where, in part because they can monopolize a broader range of animal and plant
resources, including marine-based foods (Stapp et al. 1999). Peromyscus may also
be more likely than Chaetodipus to disperse over-water because it lives and reg-
ularly forages near shore and commonly invades human encampments (P. Stapp,
pers. obs). Despite its abundance on islands, however, P. maniculatus was only
captured at one of the mainland sites, an area of coastal marsh near Punta La
Gringa. C. baileyi was captured at nine of the 14 locations on the peninsula,
although it was less abundant than C. spinatus in most areas. The vegetation and
substrate of most of the mainland sites were qualitatively similar to those of the
islands, so factors other than habitat (e.g., competition, predation) may contribute
to the local scarcity of C. baileyi, and especially P. maniculatus, on the peninsula.
It is not yet known if the insular populations of these species are distinct genet-
ically or taxonomically from those on the mainland, but they contribute to the
biological diversity of islands in the central Gulf, which are protected interna-
tionally as a Biosphere Reserve, and may be important for the conservation of
these species in Baja California.

I am indebted to Amanda Subalusky for her assistance in the field and Gary
Polis for his support of my work. This research was funded in part by the National
Science Foundation (DEB-9806657). Permission to conduct this research was
granted by the Mexican government (Permit Nos. DAN-022201, DAN-00722,
DOO.750-1502 and DAN-01529 to G. Polis), and with the generous cooperation
of Maria Luisa Jiménez, Antonio Reséndiz, Beatriz Jiménez Alvarado and Sergio
Ticul Alvarez Castenhada (Permit No. DOO 02-2193).

Literature Cited

Banks, R.C. 1967. The Peromyscus guardia-interparietalis complex. J. Mammal. 48:210—218.

Burt, W.H. 1932. Descriptions of heretofore unknown mammals from islands in the Gulf of California,
Mexico. Trans. San Diego Soc. Nat. Hist. 7:161—182.

Case, T.J. and M.L. Cody (eds.) 1983. Island biogeography in the Sea of Cortez. Univ. of California
Press, Berkeley, 502 pp:

Gastil, G., J. Minch and R.P. Phillips. 1983. The geology and ages of the islands. Pp. 13—25 in Island
biogeography in the Sea of Cortez (T.J. Case and M.L. Cody, eds.). Univ. of California Press,
Berkeley, 502 pp.

Gill, A.E. 1981. Morphological features and reproduction of Perognathus and Peromyscus on northern
islands in the Gulf of California. Am. Midl. Nat. 106:192—196.

Huey, L.M. 1964. The mammals of Baja California, Mexico. Trans. San Diego Soc. Nat. Hist. 13:85—
168.

Lawlor, TE. 1971. Distribution and relationships of six species of Peromyscus in Baja California and
Sonora, Mexico. Occ. Papers Mus. Zool., Univ. of Michigan, 661:1—22.

. 1983. The mammals. Pp. 265—289 in Island biogeography in the Sea of Cortez (TJ. Case
and M.L. Cody, eds.). Univ. of California Press, Berkeley, 502 pp.

MacArthur, R.H. and E.O. Wilson 1967. The theory of island biogeography. Monographs in Population
Biology 1, Princeton University Press, Princeton, 199 pp.

Polis, G.A and S.D. Hurd. 1996. Linking marine and terrestrial food webs: allochthonous input from
the ocean supports high secondary productivity on small islands and coastal land communities.
Am. Nat. 147:396—423.

, C.T. Jackson, and EF Sanchez Pinero. 1997. El Nino effects on the dynamics and control of

an island ecosystem in the Gulf of California. Ecology 78:1884—1897.

136 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

Smith, EA. 1992. Evolution of body size among woodrats from Baja California, Mexico. Functional
Ecology 6:265-—273.

Stapp, P., G.A. Polis, and E Sanchez Pinero. 1999. Stable isotopes reveal strong marine and El Nifio
effects on island food webs. Nature 401:467—469.

Vaughan, T:-A. and S.T. Schwartz. 1960. Behavioral ecology of an insular woodrat. J. Mammal. 61:
205-218.

Whittaker, R.J. 1998. Island biogeography. Oxford University Press, Oxford, 278 pp.

Accepted for publication 4 April 2001

Bull. Southern California Acad. Sci.
101(3), 2002, pp. 137-141
© Southern California Academy of Sciences, 2002

Interspecific Association Between Blackbrush and its Three
Commonly Associated Woody Species in Southern Nevada

Simon A. Lei

Department of Biology, WDB, Community College of Southern Nevada
6375 West Charleston Boulevard, Las Vegas, NV 89146-1139

Coleogyne ramosissima (Blackbrush) dominate relatively large areas of vege-
tation in southern Nevada and the Mojave Desert. Coleogyne shrublands are dis-
tributed at mid-elevations between Larrea tridentata-Ambrosia dumosa (creosote
bush-white bursage) shrublands below and Pinus monopohylla-Juniperus osteo-
sperma (pinyon pine-Utah juniper) woodlands above. Their current distributions
were probably developed since the last pluvial period (20,000—10,000 B.P.; Brad-
ley 1964).

Plant community can be defined as a complex assemblage of plant species
which show a definite affinity or association with each other (Kent and Coker
1992). Coleogyne plants tend to grow together with certain woody species, but
not others. These ideas can be initially represented by the concepts of positive
and negative association. Positive association implies that two plant species appear
together more often than would be expected by chance or random events. Con-
versely, negative association means that two species appear together less often
than would be expected by chance (Kent and Coker 1992).

The degree of association between species in a set of samples can be quantified.
Chi-square analysis is often used as a method of measuring association between
plant species. The. objective of this study is to quantify the degree of association
between Coleogyne ramosissima (blackbrush) and three of its commonly associ-
ated woody species, Yucca brevifolia (Joshua tree), Encelia virginensis (brittle-
bush), and Gutierrezia sarothrae (snakeweed) in the Spring Mountains and Sheep
Range of southern Nevada.

A total of 181, 100-m? circular plots were established among the 1I5 transects
that spanned the elevational distribution of Coleogyne in the Spring Mountains
(12 transects) and the Sheep Range (3 transects) in southern Nevada. Transects
began in the upper portions of the Larrea-Ambrosia shrublands, through the entire
Coleogyne belts, and terminated at the lower portions of the Pinus-Juniperus
woodlands. Transects in the Spring Mountains were subdivided into three geo-
graphical areas based on aspect. Transects contained 9 to 16 plots depending on
the range of upper and lower elevational boundaries of the Coleogyne vegetation
zone. Habitats included in the transects were classified as slopes, flat surfaces
(terraces), and dry washes. Cliffs and stream beds were excluded, but substitute
plots were randomly established at the identical elevation. All 181 plots were
placed at a fixed attitudinal interval of 65 m for each transect. All plots were
located near major access roads, but were at least 50 m away from roadways to
eliminate road effects.

Within each plot, the presence/absence (frequency) of Coleogyne, Yucca, En-
celia, and Gutierrezia plants was recorded. Three pairs of species association were

LS 7

138 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

Table 1. Summary from Chi-square (x7) analysis of the interspecific association between Coleogyne
and three of its commonly associated woody species in the Spring Mountains and Sheep Range of
southern Nevada.

Association x P-value E
Coleogyne-Yucca 18.71 0.0000 0.23
Coleogyne-Gutierrezia 1835 0.0008 0.29
Coleogyne-Encelia 5.36 0.0206 0.10

considered: Coleogyne- Yucca, Coleogyne-Gutierrezia, and Coleogyne-Encelia. In-
terspecific association between these three pairs of plant species was tested with
Chi-square analysis, and statistical significance was determined at P = 0.05 (An-
alytical Software 1994).

Coleogyne vegetation zones range from approximately 1,350 m in elevation on
north-facing slopes to over 2,000 m on south-facing slopes in the Spring Moun-
tains and Sheep Range of southern Nevada. The mean elevational range of 15
transects is 1120 to 1835 m (Lei 1995a, b).

Coleogyne was significantly positively associated with Yucca (Table 1). A
value of r = 0.0 indicates that the two species occurred together as frequently
as expected by chance; r = 1.0 implies that two species always appeared to-
gether; r = —1.0 implies that they never appeared together (Mueller-Dombois
and Ellenberg 1974). The tabular arrangement of the 2 * 2 contingency table
permits a comparison between the number of quadrats actually occupied by the
species with those expected under the hypothesis of a random dispersion of the
plants on the ground (Mueller-Dombois and Ellenberg 1974). This hypothesis
postulates that the number of occurrences of all combinations follows a predict-
able pattern as mathematically calculated by the X? distribution. Chi-square tests
are used to determine if the proportion of samples containing one species is
significantly correlated with the occurrence of a second species (Mueller-Dombois
and Ellenberg 1974).

There are reasons why positive Coleogyne-Yucca association exists at mid-
elevations in southern Nevada. Yucca plants were found in an elevational range
of 700 to 1775 m on dry slopes and terraces in this study. Yucca may be in
codominance with Larrea, Coleogyne, or Juniperus (Turner 1982). Of the three
codominant species, Yucca are most frequently associated with Coleogyne, yet
Yucca contribute relatively little to the total vegetation cover and stand compo-
sition. Yucca’s dominance is more visual because of their tall stature rather than
their high density or canopy area. Yucca usually grow on sandy, loamy, or fine
gravelly soils with minimum surface-water runoff (Turner 1982).

Although not quantitatively examined in this study, recruitment of Yucca is
largely dependent upon the existence of microclimates that occur under the can-
opies of perennial shrubs, most importantly Coleogyne. Advantages of seed ger-
mination within the canopy of a (nurse) plant may include higher soil moisture
and nutrients, along with reduced insolation, soil surface temperatures, evapo-
transpiration demand, herbivory, and reduced wind desiccation (Brittingham and
Walker 2000). Disadvantages of seed germination under a nurse plant may include
competition for resources if the adult plant has a near-surface root system, reduced

INTERSPECIFIC ASSOCIATIONS INVOLVING BLACKBRUSH PLANTS 139

net carbon gain, and allelopathy (Franco and Nobel 1989; Brittingham and Walker
2000).

Maximum seedling growth occurs with a soil temperature of 21°C (Wallace
1970); moderate air temperatures produce the highest net photosynthesis rate in
Yucca (Smith et al. 1983). Moderate plant tissue temperature appears to be the
most critical parameter favoring the survival of Yucca seedlings (Brittingham and
Walker 2000). Coleogyne plants are correlated with Yucca seedlings in greater
numbers than expected based on their density or canopy area (Brittingham and
Walker 2000). Recruitment of Yucca is based upon microhabitat alterations by
specific nurse plants, and upon subtle variations in light and shade that have
important implications on physiological/ecological requirements for germination
and survival of Yucca.

Moreover, both Coleogyne-Gutierrezia and Coleogyne-Encelia associations
were positively correlated in occurrence (Table 1), but were negatively correlated
in abundance (Data not shown). Of these two pairs of species associations, Co-
leogyne and Gutierrezia revealed a more positive correlation (Table 1). In this
study, Gutierrezia and Encelia plants were found below 2200 and 1525 m in
elevation, respectively. Gutierrezia occupied a fairly wide elevational range, from
the upper portions of Larrea-Ambrosia through the lower portions of Pinyon-
Juniperus vegetation zones. However, Encelia could not become established in
relatively high elevations above the Coleogyne zones. Gutierrezia and Encelia
were frequently established in disturbed habitats. Mature Coleogyne shrubs were
completely replaced by open stands of Gutierrezia and Encelia in fire disturbed
habitats in southern Nevada (Lei 2000). Gutierrezia made its first appearance over
other woody shrub species in areas that experienced moderate burns, suggesting
that regeneration of Gutierrezia is possible within five years after a major fire
disturbance (Lei 2000). Gutierrezia plants appear to be opportunistic and rapidly
colonize disturbed sites, presumably due to rapid reproductive potential, high seed
production, high germination rate, and early seedling establishment (Osman and
Pieper 1988; Lei 2000).

Encelia also resprouted or produced seedlings fairly rapidly after fire damage
in southern Nevada (Lei 2000). From casual observations, both Encelia and Gu-
tierrezia plants rapidly invaded open areas created by fire. Soil seed densities of
these two woody pioneer species were significantly higher in burned areas com-
pared adjacent unburned areas in southern Nevada (Lei 2001). The significantly
fewer number of seeds in burned areas suggest that Coleogyne shrubland will
require a long period of time to return to pre-burn conditions following fire dis-
turbance (Lei 2001).

Furthermore, Encelia and Gutierrezia also occurred in wash habitats within the
mature, edaphically stable Coleogyne shrublands. Although intermittent washes
are dry throughout much of the year, these washes can rapidly fill with running
surface water during and shortly after major storm events. Coleogyne plants were
nearly absent in active washes. Long-term soil stability is important for Coleogyne
plants since they typically occur on old, stable geomorphic surfaces with minimal
disturbances in southern California (Webb et al. 1987).

The Chi-square test simply relies on frequency values, based on the presence
and absence of species, to determine the degree of association between species.
Yet, this test does not incorporate other values, such as density and canopy area.

140 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

Plant species association derived from the Chi-Square analysis are strictly cor-
relative. Exactly why two species show a positive or a negative association will
require additional investigations, including various experiments under laboratory
and natural field conditions. The most common reason why two species regularly
occur together is because they share a similar set of environmental conditions.
However, further ecological investigations often reveal such an explanation to be
over-simplistic, and factors such as plant species strategies, interspecific compe-
tition, and biotic interactions also need to be taken into account (Kent and Coker
1992). In this study, the Coleogyne-Yucca association involves in both biotic and
abiotic factors. Seed germination and seedling establishment under a mature nurse
plant may alleviate some of the environmental extremes and adverse biological
interactions during the most fragile stages of the Yucca life cycle. Both Coleo-
gyne-Gutierrezia and Coleogyne-Encelia associations were positively correlated
in occurrence, but were negatively correlated in abundance. Such an inverse quan-
titative relationship is intriguing, and may indicate differing degrees of competi-
tive relations along an environmental gradient in the Spring Mountains and Sheep
Range of southern Nevada.

Acknowledgments

I sincerely appreciate Steven Lei and Yin-Chin Lei for valuable field assistance.
I also sincerely appreciate Steven Lei and two anonymous reviewers for providing
helpful comments on earlier versions of this manuscript. The Department of Bi-
ological Sciences at the University of Nevada, Las Vegas (UNLV) provided lo-
gistical support.

Literature Cited

Analytical Software. 1994. Statistix 4.1, an interactive statistical program for microcomputers. St. Paul,
Minnesota.

Bradley, W.G. 1964. The vegetation of the Desert Game Range with special reference to the desert
bighorn. TransAmerican Desert Bighorn Council 8:43—67.

Brittingham, S. and L.R. Walker 2000. Facilitation of Yucca brevifolia recruitment by Mojave Desert
Shrubs. Western North American Naturalist 60:374—383.

Franco, A.C. and P.S. Nobel. 1989. Effects of nurse plants on the microhabitat and growth of cacti.
J. Ecology 77:870—886.

Kent, M. and P. Coker. 1992. Vegetation description and analysis: a practical approach. Belhaven
Press, London, United Kingdom.

Lei, S.A. 1995a. A gradient analysis of blackbrush (Coleogyne ramosissima Torr.) communities in
southern Nevada. Unpublished thesis. University of Nevada, Las Vegas, Nevada.

. 1995b. Composition and distribution of blackbrush (Coleogyne ramosissima) communities in

southern Nevada. Pages 192-195 in Proceedings: Wildland shrub and arid land restoration.

USDA Forest Service, Rocky Mountain Research Station, Ogden, Utah.

. 2000. Postfire woody vegetation recovery and soil properties in blackbrush (Coleogyne ra-

mosissima Torr.) shrubland ecotone. Arizona-Nevada Acad. Sci. 32:105—115.

. 2001. Postfire seed bank and soil conditions in a blackbrush (Coleogyne ramosissima Torr.)
shrubland. So. Calif. Acad. Sci. 100(2):100—108.

Mueller-Dombois, D. and H. Ellenberg. 1974. Aims and methods of vegetation ecology. John Wiley
and Sons, Inc., New York.

Osman, A. and R.D. Pieper. 1988. Growth of Gutierrezia sarothrae seedlings in the field. Journal of
Range Management 41:92-93.

Smith, S.D., T.L. Hartsock, and P.S. Nobel. 1983. Ecophysiology of Yucca brevifolia, an arborescent
monocot of the Mojave Desert. Oecologia 60:10—17.

INTERSPECIFIC ASSOCIATIONS INVOLVING BLACKBRUSH PLANTS 14]

Turner, R.M. 1982. Mohave desertscrub, pp. 157-168. In: D.E. Brown, editor, Biotic communities of
the American southwest—-United States and Mexico. Desert Plants 4.

Wallace, A. 1970. Quantitative studies of roots of perennial plants in the Mojave Desert. Ecology 55:
1160-1162.

Webb, R.H., J.W. Steiger, and R.M. Turner. 1987. Dynamics of Mojave Desert scrub assemblages in
the Panamint Mountains, California. Ecology 68:478—490.

Accepted for publication 28 October 2001.

Bull. Southern California Acad. Sci.
101(3), 2002, pp. 142-143
© Southern California Academy of Sciences, 2002

Gastrointestinal Nematodes of the Isla Cerralvo Spiny Lizard,
Sceloporus grandaevus (Phrynosomatidae) from
Baja California Sur, Mexico

Stephen R. Goldberg,'! Charles R. Bursey,” and Kent R. Beaman?

| Department of Biology, Whittier College, Whittier, California 90608
e-mail: sgoldberg @ whittier.edu
* Department of Biology, Pennsylvania State University, Shenango Campus,
Sharon, Pennsylvania 16146
email:cxb13 @psu.edu
3 Section of Herpetology, Natural History Museum of Los Angeles County, 900
EOE” Bouldevard, Los Angeles, California 90007
e-mail: kbeaman@nhm.org

The Isla Cerralvo Spiny Lizard, Sceloporus grandaevus is endemic to Isla Cer-
ralvo (24°30'N, 109°40'W), Baja California Sur, Mexico. It commonly occurs in
rocky arroyos, avoiding areas devoid of vegetation (Grismer 2002). To our knowl-
edge, helminths have not been reported from S. grandaevus. We herein report two
nematode species from S. grandaevus.

Twenty Sceloporus grandaevus (mean snout-vent length, 61.1 mm + 8.9 SD,
range = 50—78 mm) collected July 1960 on the southwest portion of Isla Cerralvo
were examined (Appendix). Lizards were fixed originally in 10% formalin and
preserved in 70% ethanol. The body cavity had been opened by previous inves-
tigators; however, the internal organs were intact. The digestive tract was re-
moved, opened longitudinally and the esophagus, stomach, small and large intes-
tines were searched for helminths using a dissecting microscope. Only nematodes
were found. These were placed on microscope slides and allowed to clear in a
drop of undiluted glycerol. A coverslip was added and the nematodes were iden-
tified with a compound microscope.

Two species of Nematoda, Atractis penneri (Gambino, 1957) and Thubunaea
iguanae Telford, 1965 were found. Selected specimens were placed in vials of
70% ethanol and deposited in the United States National Parasite Collection,
(USNPC), Beltsville, Maryland: Atractis penneri USNPC 92115; Thubunaea ig-
uanae USNPC 92116. Number of individuals, prevalence (percentage of infected
lizards), mean intensity + 1 SD (mean number of helminths per infected host)
range and infection site, respectively, for each neamtode species are: Atractis
penneri, 1,216, 20%, 304 + 239 SD, 35-525, large intestine; Thubunaea iguanae,
6, 25%, 1 = 0.4 SD, 12, stomach, small! intestine:

Atractis penneri 1s widespread and has been reported in lizards of the genera
Callisaurus, Crotaphytus, Gambelia, Holbrookia, Phrynosoma, Sceloporus, Uma
and Uta occurring from the western United States, northern Mexico and Baja
California (Baker 1987).

Thubunaea iguanae was described by Telford (1965) from the stomachs of
lizards collected in California and Mexico. He reported its occurrence from Isla
San Esteban in the Gulf of California but the lizard host was not given. Thubunaea

142

NEMATODES OF ISLA CERRALVO SPINY LIZARD 143

Table 1. Reports of Atractis penneri and Thubunaea iguanae in lizards from Baja California,
Mexico.

Nematode
Lizard host Locality Prevalence Reference

Atractis penneri

Callisaurus Isla Angel de la Guarda 5/12, 42% | Gambino and Heynemann 1960

draconoides Bahia San Francisquito 2/2, 100% Gambino and Heynemann 1960
not given 13/34, 38% Gambino and Heynemann 1960

Gambelia not given 1/1, 100% Gambino and Heynemann 1960
wislizenil

Petrosaurus sp. not given 1/1, 100% Gambino and Heynemann 1960

Sceloporus Isla Cerralvo 4/20, 20% _ this study
grandaevus

Sceloporus not given 1/1, 100% Gambino and Heynemann 1960
magister

Thubunaea iguanae

Sceloporus Isla Cerralvo 5/20, 25% this study
grandaevus

Unidentified not given not stated Telford 1965
lizard(s)

iguanae is primarily known from California wehre it has been reported from
Callisaurus, Cnemidophorus, Crotaphytus, Sceloporus, Uma, Uta and Xantusia
(Baker 1987).

Sceloporus grandaevus is a new host record for Atractis penneri and Thubu-
naea iguanae and Isla Cerralvo is a new locality for both nematode species. A
list of lizards from Baja California found to harbor A. penneri and T. iguanae is
presented in Table |.

Acknowledgments

We thank David A. Kizirian (Natural History Museum of Los Angeles County)
for permission to examine the museum specimens of S. grandaevus.

Literature Cited

Baker, M. R. 1987. A synopsis of the Nematoda parasitic in amphibians and reptiles. Memorial Univ,
Newfoundland, Occas. Pap. Biol., 11:1—325.

Gambino, J. J. and D. Heyneman. 1960. Specificity and speciation in the genus Cyrtosomum (Nem-
atoda: Atractidae). Am. Midl. Nat., 63:365—382.

Grismer, L. L. 2002. Amphibians and reptiles of Baja California, including its Pacific islands and the
islands in the Sea of Cortés. Univ. Calif. Press, Berkeley, 409 pp.

Telford, S. R., Jr. 1965. A new species of Thubunae (Nematoda: Spiruroidea) from California lizards.
Jap, J. Exp. Med., 35:111—114.

Accepted for publication 26 June 2002.

Appendix

Specimens of Sceloporus grandaevus examined from the herpetology collection of the Natural
History Museum of Los Angeles County (LACM): 9935, 9940, 9942, 9948, 9956, 9963-9966, 9970,
9972, 9977, 9979, 36481-36483, 36486, 36487, 36496, 36500.

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Bull. Southern California Acad. Sci.
101(3), 2002, pp. 145-146
© Southern California Academy of Sciences, 2002

INDEX TO VOLUME 101

Abitia-Cardenas, L. Andres, see Noemi Bocanegra-Castillo

Allen, Larry G., Amy M. Findlay and Carol M. Phalen. Structure and Standing
Stock of the Fish Assemblages of San Diego Bay, California from 1994 to
1999) 49

Balart, Eduardo F, see Jose Luis Castro-Aguirre

Bearman, Kent R., see Stephen R. Goldberg

Boarman, William I. and Sharon J. Coe. An evaluation of the distribution and
abundance of Common Ravens at Joshua Tree National Park. 86

Bocanegra-Castillo, Noemi, L. Andres Abitia-Cardenas, Victor H. Cruz-Escalona,
Felipe Galvan-Magana, and Lucia Campos-Davila. Food habits of the spotted
sand bass Paralabrax maculatofasciatus (Steindachner, 1868) from Laguna
Ojo de Liebre, B-C:S.;, Mexico. 13

Bursey, Charles R., see Stephen R. Goldberg

Campos-Davila, Lucia, see Noemi Bocanegra-Castillo

Castro-Aguirre, Jose Luis, see Gorgonio Ruiz-Campos

Castro-Aguirre, Jose Luis, Gorgonio Ruiz-Campos and Eduardo E Balart. A New
Species of the Genus Li/e (Clupeiformes: Clupeidae) of the Eastern Tropical
Pacific. 1

Coe, Sharon J., see William I. Boarman

Conteras, Beatriz, see Eric Mellink

Cruz-Escalona, Victor H., see Noemi Bocanegra-Castillo

Findlay, Amy M., see Larry G. Allen

Galvan-Magana, Felipe, see Noemi Bocanegra-Castillo

Goldberg, Stephen R. and Charles R. Bursey. Helminths of the Bullfrog, Rana
catesbeiana (Ranidae), in California with Revisions to the California Anuran
Helminth List. 118

Goldberg, Stephen R., Charles R. Bursey, and Kent R. Beaman. Gastrointestinal
Nematodes of the Isla Carralvo Spiny Lizard, Sceloporus grandaaevus (Phry-
nosomatidae) from Baja California Sur, Mexico. 142

Gonzalez-Jaramillo, Monica, see Eric Mellink

Hogue, Cheryl C. and Jeanie M. Paris. Macroparasites of Pacific sanddab Cith-
arichthys sordidus (Bothidae) from polluted waters of the Palos Verdes Shelf,
southern California. 36

Lei, Simon A. Interactive Effects of Diurnal Period and Seasonality on Water
Potentials of Acacia, and Parasitic and Autoparasitic Phoradendron. 42

Lei, Simon A. Interspecific Association Between Blackbrush and its Three Com-
monly Associated Woody Species in Southern Nevada. 137

Mellink, Eric, Adriana Orozco-Meyer, Beatriz Conteras, and Monica Gonzalez-

145

146 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES

Jaramillo. Observations on nesting seabirds and insular rodents in the Middle
Sea of Cortes in 1999 and 2000. 28

Mendoza-Carranza, Manuel and Jorge A. Rosales-Casian. Feeding Ecology of
Juvenile Kelp Bass (Paralabrax clathratus) and Barred Sand Bass (P. ne-
bulifer) in Punta Banda Estuary, Baja California, Mexico. 103

Orozco-Meyer, Adriana, see Eric Mellink

Paris, Jeanie M., see Cheryl C. Hogue
Phalen, Carol M., see Larry G. Allen

Rosales-Casian, Jorge A., see Manuel Mendoza-Carranza

Ruiz-Campos, Gorgonio, see Jose Luis Castro-Aguirre

Ruiz-Campos, Gorgonio, and Jose Luis Castro-Aguirre. First Specimens of the
Fangjaw Eel Echiophis brunneus (Pisces: Ophichthidae) from the Gulf of
California, Mexico. 24

Stapp, Paul. New Records of Mammals on Small Islands in the Central Gulf of
California, Mexico. 131

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Assemble the manuscript as follows: cover page (with title, authors’ names and addresses), abstract, introduction,
methods, results, discussion, acknowledgements, literature cited, appendices, tables, figure legends, and figures.

A cover illustration pertaining to an article in the issue or one of general scientific interest will be printed on the
cover of each issue. Such illustrations along with a brief caption should be sent to the Editor for review.

PROCEDURE

All manuscripts should be submitted to the Editor, Daniel A. Guthrie, W. M. Keck Science Center, 925 North
Mills Avenue, Claremont, CA 91711. Authors are requested to submit the names, addresses and specialities of
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CONTENTS

Feeding Ecology of Juvenile Kelp Bass (Paralabrax clathratus) and Barred
Sand Bass (P nebulifer) in Punta Banda Estuary, Baja California,
Mexico. Manuel Mendoza-Carranza and Jorge A. Rosales-Casian

Helminths of the Bullfrog, Rana catesbeiana (Ranidae), in California with
Revisions to the California Anuran Helminth List. Stephen R.
Goldberg and Charles R. Bursey 22.0500)

New Records of Mammals on Small Islands in the Central Gulf of California,
México. Paul Stapp. 2000 oN

Interspecific Association Between Blackbrush and its Three Commonly
Associated Woody Species in Southern Nevada. Simon A. Lei _

Gastrointestinal Nematodes of the Isla Cerralvo Spiny Lizard, Sceloporus
grandaevus (Phrynosomatidae) from Baja California Sur, Mexico.
Stephen R. Goldberg, Charles R. Bursey, and Kent R. Beaman ____

INDEX TO VOLUME JOU ce er

Cover: Seal of the Academy

103

118

131

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